Low-profile pelvic fixation with sacral alar-iliac screws

Background

In the last years, a new technique for pelvic fixation using ‘sacral alar-iliac’ screws has been proposed as an alternative to the classic ‘iliac wing’ screws and the old Galveston technique.

Methods

The authors provide a ‘step-by-step’ review of the technical details regarding this technique, as well as some important anatomical and radiological landmarks for its successful performance.

Conclusions

‘Sacral alar-iliac’ screws provide several advantages in relation to pelvic fixation with iliac bolts such as: better alignment with the rods, use of a ‘low-profile’ screw, and fixation of the sacroiliac (SI) joint, which avoids postoperative SI joint-related pain.     

Treatment of periprosthetic tibial plateau fractures in unicompartmental knee arthroplasty: plates versus cannulated screws

Introduction

Periprosthetic tibial plateau fractures (TPF) are rare but represent a serious complication in unicompartmental knee arthroplasty. The most common treatment for these fractures is osteosynthesis with cannulated screws or plates. The aim of this study was to evaluate two different treatment options for periprosthetic fractures. The hypothesis was that angle-stable plates show significantly higher fracture loads than fixation with cannulated screws.

Materials and methods

Twelve matched, paired fresh-frozen tibiae with periprosthetic TPF were used for this study. In Group A, osteosyntheses with cannulated screws were performed, whereas in Group B plates fixated the periprosthetic fracture. DEXA bone density measurement and standard X-rays (AP and lateral) were performed before loading the tibiae under standardised conditions with a maximum load of up to 10.0 kN. After the specimens had been loaded, fracture patterns and fracture loads were analysed and correlated with BMD, BMI, bodyweight (BW), age and size of the tibial implant.

Results

In the plate group all tibiae fracture occured with a median load of F _max = 2.64 (0.45–5.68) kN, whereas in the group with cannulated screws fractures occurred at a mean load of F _max = 1.50 (0.27–3.51) kN. The difference was statistically significant at p < 0.05.

Discussion

Angle-stable plates showed significantly higher fracture loads than fixation with cannulated screws. Cannulated screws show a reduced stability of the tibial plateau. Therefore in periprosthetic TPF, osteosyntheses with angle-stable plates should be recommended instead of cannulated screws.     

3D-navigierte Fersenbeinosteosynthese

Background

It is hypothesized that misplacement of sustentacular screws during osteosynthesis of intraarticular calcaneal fractures can be reduced with the help of navigation. A method for three-dimensional (3D) navigated placement of sustentacular screws for treating intraarticular calcaneal fractures is presented and evaluated.

Material and Methods

11 consecutive patients with 15 intraarticular calcaneal fractures were treated using 3D navigation. In 12 cases osteosynthesis was done through an extended lateral approach; in three cases, it was achieved through a minimally invasive percutaneous approach. For verification and documentation of the placed screws, a second 3D scan was performed.

Results

A total of 20 screws were placed using 3D navigation. None of the navigated screws was misplaced. Extra operating time due to navigation averaged 11.9 minutes (±2.2 min).

Conclusion

Through a combination of intraoperative 3D imaging and navigation, placement of sustentacular screws is possible and can yield precise and reliable results. Especially in minimally invasive treatment, a high quality of osteosynthesis can be achieved.     

Clinical and radiologic outcomes associated with the use of dynamic locking screws (DLS) in distal tibia fractures

Background

The locked screw plate construct is often cited as being too rigid and prolonging healing in patients with metaphyseal fractures. The newly introduced dynamic locking screws (DLS) allow 0.2 mm of axial motion, which should optimize healing near the near cortex. The purpose of this study was to analyze the clinical results of dynamic locking screws in distal tibia fractures.

Methods

Data were acquired retrospectively. Only distal meta-diaphyseal tibia fractures treated with minimally invasive plate osteosynthesis and DLS were evaluated. Cortical and locking head screws were used for distal plate fixation to minimize soft tissue irritation over the medial malleolus, and DLS were used in the proximal plate fixation. Clinical and radiographic data were evaluated after 6 weeks, 3 months, 6 months and 1 year until fracture union.

Results

Twenty-two patients were treated with minimally invasive plate osteosynthesis and DLS. Six patients could not be evaluated because they returned to a foreign residence after the procedure. Fourteen fractures healed after a mean of 3.1 months. Two fractures with insufficient reduction showed delayed union and healed after 9 and 9.5 months, respectively. The callus index peaked at 6 months.

Conclusions

Dynamic fracture fixation might be a promising concept to reduce the frequency of metaphyseal non-unions in distal tibia fractures. But nevertheless, the dynamic construct cannot compensate for insufficient reduction.

     

13-Year experience in external fixation of the pelvis: complications,reduction and removal

Purpose

To evaluate the complications associated with anterior pelvic external fixation and the success of this device in maintaining reduction when used in conjunction with sacroiliac screws.

Methods

Through a retrospective clinical study at an academic Level I Trauma Center, 129 patients fit the criteria for inclusion with a mean duration of anterior pelvic external fixation of 62 days and mean follow-up of 360 days. Charts were reviewed for complications postoperatively. The symphysis diastasis, vertical displacement and posterior displacement of each hemipelvis were quantified from pelvic radiographs.

Results

Of the 129 patients receiving anterior pelvic external fixation, 14 (10.9 %) presented to an emergency department for problems with their anterior pelvic external fixation. Of these 14 patients, 7 (5.4 %) required readmission, all for infectious concerns necessitating IV antibiotics. 6 (4.7 %) required formal operative debridement and device removal. 13 patients (10.1 %) had superficial pin site infections successfully treated with oral antibiotics. Reduction was maintained (rated as fair, good or excellent) in all patients with radiographic follow-up (n = 74, average radiographic follow-up of 216 days) following removal of their anterior pelvic external fixation. 38 patients (30.4 %) had their anterior pelvic external fixation removed in clinic, while 87 (69.6 %) had formal removal in the operating room.

Conclusion

While previous data suggest high complication rates in definitive anterior pelvic external fixation, we present the largest cohort of patients receiving anterior pelvic external fixation and sacroiliac screws, demonstrating a low complication rate while maintaining reduction of the pelvic ring. In addition, we found that these devices could be reliably removed in a clinic setting.

     

A new fixation method for Hoffa fracture

Purpose

To investigate the clinical effect of a new fixation method for Hoffa fractures.

Methods

We treated eleven patients with Hoffa fracture using the new fixation method (fixation with one screw inserted from the femoral intercondylar notch and two screws inserted from the nonarticular lateral (or medial) surface of the fractured condylar fragment; the two sets of screws were crossed).

Results

After an average follow-up period of 24 months (range 5–28 months), all fractures had healed. The average healing time was 11.6 weeks (range 9–14 weeks). On the version of the Knee Society Score modified by Dr. John Insall in 1993, the average score was 174.6 points (range 125–199 points).

Conclusions

The new fixation method for Hoffa fracture is effective, and may provide a new way to treat Hoffa fractures.     

Position of polyaxial versus monoaxial screws in locked plating for proximal humeral fractures: analysis of a prospective randomized study

Background

Aim of the study was to compare the chosen position of polyaxial locking screws with the position of monoaxial screws in the humeral head of proximal humeral fractures treated by locked plating.

Methods

In a prospective randomized observational study, 124 consecutive patients (mean age 70.9 ± 14.8 years) sustaining a displaced proximal humeral fracture were treated with either monoaxial or polyaxial screw-inserted locking plate fixation. The chosen positions of locking screws were identified from standardized postoperative radiographs in anteroposterior and outlet-view, with regard to a regional mapping of the humeral head.

Results

In monoaxial locking technique, a mean of 6 screws purchased the humeral head (95 % CI 5.1–6.2), and in polyaxial locking technique, a mean of 4 screws (95 % CI 3.3–4.5), respectively. Screws were placed in the regions superolateral: monoaxial 24.8 %, polyaxial 20.7 % (p = 0.49); superomedial: monoaxial 21.9 %, polyaxial 20.0 % (p = 0.433); inferolateral: monoaxial 32.5 %, polyaxial 35.0 % (p = 0.354); inferomedial: monoaxial 20.8 %, polyaxial 24.2 % (p = 0.07), superoposterior: monoaxial 45.5 %, polyaxial 30.8 % (p = 0.57); superoanterior: monoaxial 4.4 %, polyaxial 8.3 % (p = 0.33); inferoposterior: monoaxial 22.5 %, polyaxial 29.8 % (p = 0.49) and inferoanterior: monoaxial 27.5 %, polyaxial: 31.2 % (p = 0.09).

Conclusion

The chosen screws’ position in monoaxial and polyaxial locking plate fixation of displaced proximal humeral fractures do not differ significantly. However, loss of fixation is observed more frequently if the fixation did not include at least one screw within the superoposterior region of the humeral head, suggesting that a screw purchasing the superoposterior region is beneficial in locked plating of proximal humeral fractures.

Level of evidence

Treatment Study, Level II.     

Can a Modified Anterior External Fixator Provide Posterior Compression of AP Compression Type III Pelvic Injuries?

Background

Current anterior fixators can close a disrupted anterior pelvic ring. However, these anterior constructs cannot create posterior compressive forces across the sacroiliac joint. We explored whether a modified fixator could create such forces.

Questions/purposes

We determined whether (1) an anterior external fixator with a second anterior articulation (X-frame) would provide posterior pelvic compression and (2) full pin insertion would deliver higher posterior compressive forces than half pin insertion.

Methods

We simulated AP compression Type III instability with plastic pelvis models and tested the following conditions: (1) single-pin supraacetabular external fixator (SAEF) using half pin insertion (60 mm); (2) SAEF using full pin insertion (120 mm); (3) modified fixator with X-frame using half pin insertion; (4) modified fixator using full pin insertion; and (5) C-clamp. Standardized fracture compression in the anterior and posterior compartment was performed as in previous studies by Gardner. A force-sensitive sensor was placed in the symphysis and posterior pelvic ring before fracture reduction and the fractures were reduced. The symphyseal and sacroiliac compression loads of each application were measured.

Results

The SAEF exerted mean compressions of 13 N and 14 N to the posterior pelvic ring using half and full pin insertions, respectively. The modified fixator had mean posterior compressions of 174 N and 222 N with half and full pin insertions, respectively. C-clamp application exerted a mean posterior load of 407 N.

Conclusions

Posterior compression on the pelvis was improved using an X-frame as an anterior fixation device in a synthetic pelvic fracture model.

Clinical Relevance

This additive device may improve the initial anterior and posterior stability in the acute management of unstable and life-threatening pelvic ring injuries.     

Accuracy of screw fixation using the O-arm<Superscript>®</Superscript> and StealthStation<Superscript>®</Superscript> navigation system for unstable pelvic ring fractures

Purpose

Screw fixation for unstable pelvic ring fractures is generally performed using the C-arm. However, some studies reported erroneous piercing with screws, nerve injuries, and vessel injuries. Recent studies have reported the efficacy of screw fixations using navigation systems. The purpose of this retrospective study was to investigate the accuracy of screw fixation using the O-arm^® imaging system and StealthStation^® navigation system for unstable pelvic ring fractures.

Methods

The participants were 10 patients with unstable pelvic ring fractures, who underwent screw fixations using the O-arm StealthStation navigation system (nine cases with iliosacral screw and one case with lateral compression screw). We investigated operation duration, bleeding during operation, the presence of complications during operation, and the presence of cortical bone perforation by the screws based on postoperative CT scan images. We also measured the difference in screw tip positions between intraoperative navigation screen shot images and postoperative CT scan images.

Results

The average operation duration was 71 min, average bleeding was 12 ml, and there were no nerve or vessel injuries during the operation. There was no cortical bone perforation by the screws. The average difference between intraoperative navigation images and postoperative CT images was 2.5 ± 0.9 mm, for all 18 screws used in this study.

Conclusion

Our results suggest that the O-arm StealthStation navigation system provides accurate screw fixation for unstable pelvic ring fractures.

     

Intramedullary tibial nailing of distal tibiofibular fractures: additional fibular fixation or not?

Introduction

The anatomy of the distal tibia accounts for reduced biomechanical stability and higher complication rates when treating distal tibiofibular fractures with an intramedullary tibia nail (IMTN). The goal of this study was to identify variables that affect the stability of IMTN. We assessed the value of additional fibular fixation, angular stable interlocking screws (ASLS) and multiplanar screw configuration in IMTN.

Patients and methods

A retrospective cohort study was performed including 184 distal tibial fractures and associated fibula fracture treated with IMTN. Relevant demographic, fracture-related (type and level of the tibia and fibula fracture) and operative variables (depth of the nail, screw type and configuration, use of polar screws, fibular fixation) were studied. Coronal and sagittal alignment was assessed directly and 3–6 months after IMTN. Loss of reduction (LOR) was classified as 5–9° or ≥10°.

Results

48.4% of the patients showed ≥5° LOR in one or both planes. Coronal LOR 5°–9° significantly correlated with low tibial fractures (p = 0.034), AO/OTA type 43 distal tibial fractures (p = 0.049), and sagittal LOR 5°–9° (p = 0.015). Although sagittal LOR 5°–9° was associated with fibular fractures (non-fixated suprasyndesmotic, p = 0.011), conversely we could not demonstrate the added value of (suprasyndesmotic) fibula fixation in IMTN. Coronal LOR ≥10° significantly correlated with AO/OTA type 43 distal tibial fractures (p = 0.009). In contrast to multiplanar configuration, we found a clear benefit of ASLS in distal IMTN locking.

Conclusions

The level of the tibial fracture (AO/OTA type) and (suprasyndesmotic) fibular fractures were the main determinants of LOR after IMTN. ASLS was found to increase the stability of IMTN. Due to heterogeneity, however, we could not demonstrate the value of fibular fixation in IMTN. Therefore, a future prospective study with uniform treatment strategy for IMTN of distal tibiofibular fractures, with or without fixation of the fibula, is mandatory.

     

AO extra-articular distal humerus locking plate: extended spectrum of usage in intra-articular distal fractures with metaphyseal extension—our experience with 20 cases

Background

LCP extra-articular plate designed by AO has been used in extra-articular fractures of the distal humerus, mal-unions, and nonunions of the distal humerus. They provide anatomically shaped and angular stable fixation system for extra-articular fractures of the distal humerus. We extended the usage spectrum of this plate to the extra-articular with intra-articular distal humerus fractures and compared it with the standard orthogonal locking plate fixation.

Methods

We included 22 consecutive distal humerus intra-articular fractures with metaphyseal and diaphyseal extension into the study. Each case underwent osteosynthesis with LCP extra-articular plate fixation and augmented the intra-articular fragments with 4.0 mm partially threaded cancellous screws. The cost, surgical time, VAS, Modified Mayo Clinic Performance Index for elbow, and postoperative complications were recorded. The radiological union and postoperative elbow range of motion were assessed at 6 weeks, 6, and 12 months of follow-up. Twenty cases completed the scheduled follow-up. The results were compared with retrospective data of 20 cases from our institute where similar fractures were treated with standard orthogonal LCP distal humerus plate (LCPDHP).

Results

The radiological union rates and the range of motion at 6 weeks, 6, and 12 months in both the groups were comparable and did not vary significantly (p > 0.05). The cost and operative time with the LCP extra-articular plates were significantly less (p < 0.05) when compared to the group LCPDHP.

Conclusion

The usage spectrum of extra-articular distal humerus locking plate can be extended to intra-articular fractures. It provides good results and significantly reduces the cost and operative time.     

Implantatentfernung nach Beckenringfraktur

Background

Pelvic ring fractures are considered as rare injuries. Minimally invasive sacroiliac screw fixation has been used increasingly in recent years as an operative strategy for the treatment of these injuries, if the dorsal pelvic ring needed to be addressed. Treatment options for the anterior pelvic ring comprise plates, screws or external fixation.

Method

Based on the limited number of publications on this subject and our own experience with 80 patients who suffered pelvic ring B- or C-type injuries during a period of 8 years we are able to show that the indication for hardware removal in the pelvic ring should be strictly defined.

Results

In some cases like external fixation, implant-associated infection, malpositioning, allergic implant reaction, critical soft tissue covering, palpable hardware and consolidated juvenile fractures implant removal is certainly indicated. In patients without symptoms and in patients with trauma-associated symptoms which are not definitely associated with the hardware, the removal should be only indicated after thorough consideration of the risks versus the benefits and additionally by taking the initial injury pattern into account. If despite all these objections the hardware removal has been indicated it should always be considered that hardware removal may be challenging with several possible severe complications.     

Minimally invasive periprosthetic plate osteosynthesis using the locking attachment plate

Objective

Stable fixation of periprosthetic or periimplant fractures with an angular stable plate and early weight bearing as tolerated.

Indications

Periprosthetic femur fractures around the hip, Vancouver type B1 or C. Periprosthetic femur and tibia fractures around the knee. Periprosthetic fractures of the humerus. Periimplant fractures after intramedullary nailing.

Contraindications

Loosening of prosthesis. Local infection. Osteitis.

Surgical technique

Preoperative planning is recommended. After minimally invasive fracture reduction and preliminary fixation, submuscular insertion of a large fragment femoral titanium plate or a distal femur plate. The plate is fixed with locking head screws and/or regular cortical screws where possible. If stability is insufficient, one or two locking attachment plates (LAP) are mounted to the femoral plate around the stem of the prosthesis. After fixing the LAP to one of the locking holes of the femoral plate, 3.5 mm screws are used to connect the LAP to the cortical bone and/or cement mantle of the prosthesis.

Postoperative management

Weight bearing as tolerated starting on postoperative day 1 is suggested under supervision of a physiotherapist.

Results

In 6 patients with periprosthetic fractures and 2 patients with periimplant fractures, no surgical complications (e.g., wound infection or bleeding) were observed. The mean time to bony union was 14 weeks. No implant loosening of the locking attachment plate was observed. At the follow-up examination, all patients had reached their prefracture mobility level.     

Displaced inferior ramus fractures as a marker of posterior pelvic injury

Introduction

Injuries to the anterior or posterior pelvic ring rarely occur in isolation. Disruption to the anterior pelvic ring, indicated by a fracture of the superior or inferior pubic ramus, or injury to the pubic symphysis, may be indicative of additional pelvic ring disruption. The purpose of this retrospective study was to determine whether displaced inferior pubic ramus fractures warrant a more detailed investigation of the posterior ring in an effort to predict unstable posterior pelvic ring injuries.

Materials and methods

All patients with a displaced inferior ramus fracture on AP pelvic radiograph were identified at a single level I trauma center over a 5-year period. Complete pelvic radiographs and computed tomography scans were then evaluated for additional pelvic ring injuries. The data were analyzed using the chi-square test to determine the association between inferior ramus fractures and posterior pelvic ring injury.

Results

Sixty-three of the 93 patients with a fracture of the inferior ramus (68 %) were found to have a posterior ring injury; 60 % of these injuries were unstable. Patients with concurrent superior ramus fractures were more likely to have a posterior ring injury (p < 0.001) and an unstable pelvis (p = 0.018). Of those with a displaced unilateral inferior ramus fracture, parasymphyseal involvement was associated with higher incidence of posterior ring injury (p = 0.047) and pelvic instability (p = 0.028).

Conclusion

The anterior pelvic ring can be used to help identify unstable injuries to the posterior pelvis. Patients with displaced inferior pubic ramus fractures warrant a detailed examination of their posterior ring to identify additional injuries and instability.     

Repeat LISS treatment for femoral shaft fractures due to hardware failure: a retrospective analysis of eleven cases

Objective

To evaluate the effectiveness of a replating technique having a less-invasive stabilization system (LISS) for femoral shaft fractures due to LISS failure in adults.

Patients and methods

There were 11 patients with hardware failure of LISS for femoral shaft fractures, on an average of 50 days after the primary operation. The failed implants were removed, and the fractures were replated with a LISS following the rationale of biological osteosynthesis. Radiological fracture union and incidence of postoperative complications were employed to evaluate the effectiveness of this replating technique for femoral shaft fractures.

Results

Operative duration including removing failed hardware and replating fractures averaged 81.5 min, with an average blood loss of 330 ml. Patients had an average follow-up of 25.7 months. Radiological evaluation indicated that fracture union occurred in an average of 4.4 months in all patients. The length and alignment of the affected limb were satisfactory, and hardware failure did not recur.

Conclusion

The replating technique with LISS for femoral shaft fractures due to hardware failure of LISS can obtain satisfactory results when the appropriate rationale of biological osteosynthesis and functional exercise is followed.     

Intraoperative evaluation of dorsal screw prominence after polyaxial volar plate fixation of distal radius fractures utilizing the Hoya view: a cadaveric study

Background

The irregular nature of the dorsal surface of the distal radius makes it difficult to detect prominent screws with volar plate fixation for distal radius fractures using standard fluoroscopic images. This study evaluates the accuracy of a new radiographic method, the Hoya view, for the assessment of dorsal cortical screw penetration with volar plate fixation.

Methods

Eight cadaveric upper extremities underwent application of a volar distal radius plate with polyaxial locking screws placed distally. Utilizing a mini C-arm, lateral and Hoya views were obtained with notation of any dorsal cortical screw prominence. Dissection of the cadavers was then performed for direct visualization of screw prominence. The screws were then exchanged sequentially for screws 2-mm longer than their initial measurements with repeated imaging and direct visualization.

Results

The Hoya view revealed that 9.4 % of the screws penetrated the dorsal cortex with an average screw prominence of 1.08 mm (range 0.5–2 mm). None of the six prominent screws were detected with lateral views. With the Hoya view, six of six prominent screws were identified. With locking screws exchanged for screws 2-mm longer, 76.6 % of the screws had violated the dorsal cortex; of these, 24.5 % were detected with lateral imaging versus 100 % with the Hoya view.

Conclusions

This study supports the intraoperative use of the Hoya view to evaluate screw length and dorsal cortical screw penetration in volar plate fixation of distal radius fractures. However, this view may be difficult to obtain in patients with limitations in elbow or shoulder range of motion.     

Unstable atlas fracture treatment by anterior plate C1-ring osteosynthesis using a transoral approach

Study design

A retrospective study was conducted to evaluate anterior plate fixation of unstable atlas fractures using a transoral approach.

Objective

To further investigate the safety and efficacy of this surgical technique, as there is currently a paucity of available data.

Summary of background data

While most atlas fractures can be managed by external immobilization with favorable results, surgery is usually preferable in highly unstable cases. Surgical stabilization is most commonly achieved using a posterior approach with fixation of C1–C2 or C0–C2, but these techniques usually result in loss of joint function and cannot fully stabilize anterior arch fractures of the atlas. Although a transoral approach circumvents these issues, only nine cases were described in the literature to our knowledge.

Methods

Twenty patients with unstable atlas fractures were treated with this technique during a 6-year period. Screw and plate placement, bone fusion, and integrity of spinal cord and vertebral arteries were assessed via intraoperative and follow-up imaging. Neurologic function, range of motion, strength, pain levels, and signs of infection were assessed clinically upon follow-up.

Results

There were no incidents of screw loosening or breakage, plate displacement, spinal cord injury, or vertebral artery injury. A total of 20 plates were placed and all 40 screws were inserted into the atlas lateral masses. CT scans demonstrated that two screws were placed too close to the vertebral artery canal, but without clinical consequences. Imaging demonstrated that bone fusion was achieved in all cases by 6 months postoperatively, without intervertebral instability. No plate-related complications were observed in any patients during the follow-up period.

Conclusions

C1 anterior plate fixation using a transoral approach appears to be a safe, reliable, and function-preserving surgical method for the management of unstable atlas fractures. For this type of fracture, a transoral approach with anterior fixation should be considered as an alternative to posterior approaches or conservative treatments.     

Locking versus standard screw fixation for acetabular cups: is there a difference?

Introduction

Total hip replacement has been established as a valid treatment option for displaced subcapital fractures. However, insufficient primary fixation may be the reason for early loosening in these osteoporotic patients. Primary fixation of the cup is usually achieved by press-fit fixation that can be enhanced using screws. Locking the screws into their respective cups may seem to improve the primary fixation of the construct, as locked plates proved superior fixation for osteoporotic fractures.

Methods

The study consisted of three groups: in each group, three cups were fixed into blocks of foam bone using press-fit technique. In the first group, no additional screws were used, in the second group two standard screws were inserted, while in the third group two acetabular screws were cemented into the cup to simulate locked screw fixation. Load was applied onto the rim of the acetabular component to cause shearing between the cup and the block. Cup fixation was examined by a loading machine that acquired load versus displacement. The stiffness (load vs. displacement) was calculated.

Results

Screws, either locked or non-locked, enhanced cup fixation by 26 % (p value <0.01). No significant changes were found between the locking and non-locking screws groups.

Discussion

These experimental results indicate that acetabular screws enhance primary cup fixation. This may become significant in conditions where the acetabular bone stock is suboptimal, such as when performing total hip arthroplasty after displaced subcapital fractures. However, there is no superiority for locked screws over standard screw fixation.     

Risk factors for nonunion in 337 displaced midshaft clavicular fractures treated with Knowles pin fixation

Background

Clavicular fractures account for nearly 10 % of all fractures, and the majority of those fractures involve the midshaft. Historically, these fractures were treated nonoperatively; however, recent data suggest an increased risk of nonunion and symptomatic malunion for displaced, comminuted midshaft clavicular fractures treated conservatively. Surgical intervention via plate osteosynthesis or intramedullary fixation with pins, nails, or screws has been shown to reduce, but not eliminate, this risk. Identification of risk factors predictive of nonunion would improve the overall management of displaced, comminuted midshaft clavicular fractures.

Methods

The medical records of 337 consecutive patients who underwent Knowles pin fixation and supplemental cerclage for the treatment of displaced, comminuted midshaft clavicular fractures between April 2007 and March 2009 were retrospectively reviewed. The records of the mechanism of injury, side of injury, Robinson fracture classification, presence of associated injuries, cerclage material, and patient-related variables, including diabetes mellitus, hypertension and smoking, were analyzed. Variables were assessed by univariate and multivariate analysis to identify those factors significantly associated with the development of fracture nonunion.

Results

A total of 19 nonunions occurred. Increasing age and use of wire for supplemental cerclage fixation were significantly associated with an increased risk for fracture nonunion (p < 0.001). Although suggested as predictors of nonunion in other studies, female gender and fracture severity were not significantly associated with nonunion.

Conclusions

Nonunion remains a significant complication in the treatment of displaced, comminuted midshaft clavicular fractures even with intramedullary fixation. Use of absorbable suture in place of wire for cerclage fixation and careful selection of treatment strategy in the elderly may reduce the risk for nonunion.