Vancouver B2 Peri-Prosthetic Fractures in Cemented Femoral Implants can be Treated With Open Reduction and Internal Fixation Alone Without Revision.

BACKGROUND: The aim of this study is to assess the outcomes of 52 consecutive Vancouver B2 peri-prosthetic fractures around cemented polished double-tapered stems treated by open reduction and internal fixation in 2 trauma centers in 2 countries. METHODS: Outcomes included modified Harris Hip Score (mHHS), Harris Pain Score, and return to pre-injury mobility. Fracture healing was assessed; implant subsidence measured and complications including re-operations reported. RESULTS: No patient was lost to follow-up. Median patient age at operation was 82 years (range 43-98); Harris pain scores showed minimal pain (median 42, range 10-44) at latest follow-up. Median total subsidence at 1 year was 1.1 mm (range 0-5.4), the majority of which occurred within the cement mantle. No subsequent femoral stem revision was required (median 2.9 years, 0-10); however, there were 3 re-operations: 1 re-operation for pre-existing recurrent dislocation involving head liner exchange and 2 for repeat fixation due to metal fatigue. Two additional fractures occurred below the new plating, requiring further plating whilst still retaining the original stems. CONCLUSION: Anatomical reduction and open reduction and internal fixation of Vancouver B2 peri-prosthetic fractures should be considered as an appropriate treatment solution for frail elderly patients with a peri-prosthetic fracture around cemented polished double-tapered stems.

Testing the Hip Abductor Muscle Strength of Older Persons Using a Handheld Dynamometer.

OBJECTIVE: To investigate the reliability of a clinically applicable method of dynamometry to assess and monitor hip abductor muscle strength in older persons. DESIGN: Bilateral isometric hip abductor muscle strength measured with a handheld dynamometer, patients supine with the contralateral hip positioned directly against a wall for stabilization. Reliability determined by comparing intra-assessor and inter-assessor results and comparison to a criterion standard (stabilized dynamometer with patients in the standing position). SETTING: UniSA Nutritional Physiology Research Centre. PARTICIPANTS: Twenty-one patients older than 65 years were recruited from the Royal Adelaide Hospital. MAIN OUTCOME MEASURES: Intraclass correlation coefficients (ICCs), bias, and limits of agreement calculated to determine reliability. RESULTS: Intra-assessor and inter-assessor ICCs were high (0.94 and 0.92-0.94, respectively). There was no intra-assessor bias and narrow limits of agreement (±2.4%). There was a small inter-assessor bias but narrow limits of agreement (0.6%-0.9% and ± 2.3%, respectively). There was a wide variation comparing results to the criterion standard (±5.0%-5.2% limits of agreement), highlighting problems attributed to difficulties that the test population had with the standing position used in the criterion standard test. CONCLUSIONS: Testing older persons' hip abductor muscle strength while in the supine position with optimal pelvic stabilization using a handheld dynamometer is highly reliable. While further studies must be done to assess patients with specific pathologies, this test has potential application to monitor and evaluate the effects of surgical interventions and/or rehabilitation protocols for a variety of conditions affecting hip abductor function such as hip fractures and arthritis.

Influence of Fracture Stability on Early Patient Mortality and Reoperation After Pertrochanteric and Intertrochanteric Hip Fractures.

OBJECTIVES: To determine the influence of fracture stability on early patient mortality and complications requiring reoperation after trochanteric hip fracture. DESIGN: Prospective consecutive cohort study. SETTING: The orthopaedic unit of a public teaching hospital. PARTICIPANTS: Seven hundred twenty-eight patients with 743 consecutive stable (n = 446) pertrochanteric and unstable (n = 297) pertrochanteric or intertrochanteric fractures (median age: 84 years, 71% females) resulting from a low-impact injury and surgically managed. Mean follow-up of surviving patients was 4 years (range: 2-6 years). INTERVENTION: Fracture fixation by dynamic hip screw extramedullary device or intramedullary nail (Austofix or Gamma3) based on surgeon preference. MAIN OUTCOME MEASURES: Mortality within 6 and 12 months and surgical complications requiring device reoperation within 12 months of surgery (multivariate logistic regression and Kaplan-Meier survival analyses). RESULTS: Patients with unstable fractures were at 1.61 times (95% confidence interval: 1.18-2.21, P = 0.003) and 1.37 times (95% confidence interval: 1.02-1.83, P = 0.037) greater odds of dying within 6 and 12 months, respectively, than those with stable fractures. Older age, male gender, higher American Society of Anesthesiologists classification, in residential care, and inpatient-reported medical complications were also independent risk factors for early mortality. Increasing fracture instability and fixation using the Austofix nail were associated with early device reoperation. Comparable results were reported for the dynamic hip screw and Gamma3 nail, although the Gamma3 nail may offer advantages for more complex unstable fractures. CONCLUSIONS: Fracture instability influences early mortality after surgical fixation of trochanteric hip fracture. The Austofix double lag screw device had suboptimal results. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Is internal fixation alone advantageous in selected B2 periprosthetic fractures?

BACKGROUND: Revision surgery is currently the recommended treatment for Vancouver B2 femoral periprosthetic fractures, but isolated open reduction and internal fixation (ORIF) might be an effective treatment for these fractures around cemented collarless polished tapered (CCPT) stems, as these stems can re-engage in the cement mantle, regaining stability following internal fixation. The aim of this study was to determine the operative risks, post-operative complications, and radiographic and functional outcomes in two cohorts of Vancouver B2 femoral fractures around CCPT stems treated either by ORIF alone or revision surgery. METHODS: The results of 12 patients with B2 periprosthetic fractures around a CCPT stems treated by ORIF alone (median follow-up 67 months) were compared with those of nine patients with a similar fracture treated by revision surgery (median follow-up 59 months). RESULTS: All fractures treated by ORIF alone healed and all stems restabilized and remained stable within their original cement mantle. These patients had significantly shorter overall operating room times (P = 0.002), surgical times (P = 0.002) and required fewer units of blood transfusion (P = 0.008) than patients in the revision cohort. In the ORIF cohort, one patient had two dislocations. In the revision cohort, one patient had delayed wound healing, a second patient had delayed wound healing and two dislocations, and a third patient had two dislocations. CONCLUSION: Although further studies with larger numbers are required, treatment of these fractures with ORIF alone may be a viable alternative to revision surgery as it reduces the operative risks involved.

Tibial interference screw fixation in anterior cruciate ligament reconstruction with and without autograft bone augmentation.

PURPOSE: Because tibial fixation of soft-tissue grafts in anterior cruciate ligament (ACL) reconstruction is problematic, this study aimed to develop a means of delivering bone graft evenly around tendon autograft and define any mechanical, radiologic, or histologic benefit using an ovine model. METHODS: A device to deliver bone graft evenly throughout the tibial tunnel was developed. Forty mature sheep underwent simulated quadruple hamstring tendon-ACL reconstruction by use of a bioresorbable interference screw, either with or without bone graft augmentation of the tibial tunnel. Endpoint data were derived at time 0 and after 6 weeks in vivo. Radiostereometric analysis provided quantitation of the translational characteristics; computed tomography evaluated tunnel volume, and measures of yield strength and stiffness were obtained. Sequential fluorochrome administration assessed bone formation, and light microscopy surveyed the biological response. RESULTS: Radiostereometric analysis highlighted differences in the translational characteristics of ACL-deficient knees when compared with intact knees. Reconstructed knees (with or without autograft) showed significantly greater translation when compared with unoperated knees at 6 weeks; autograft bone augmentation provided no benefit. Neither tunnel volume nor yield strength nor stiffness was improved with the addition of autograft bone. No untoward histologic responses were observed. Bone apposition rates were similar between treatment groups. An even distribution of bone graft throughout the tunnels was observed. CONCLUSIONS: This model has confirmed the ability of the bone graft-delivery system to evenly distribute bone graft throughout the tunnels. However, the study has failed to show improvement in stability or fixation strength after augmentation with autograft bone. CLINICAL RELEVANCE: The autograft bone-delivery system may provide a means of establishing an osteoconductive/inductive environment. At this early juncture (6 weeks), no benefit could be defined. Its use in combination with bone morphogenetic proteins or stem cells may provide more rapid fixation, rehabilitation, and reconstitution of bone volume within the tunnel.

Biodegradable injectable polyurethanes: synthesis and evaluation for orthopaedic applications.

Biodegradable polyurethanes offer advantages in the design of injectable or preformed scaffolds for tissue engineering and other medical implant applications. We have developed two-part injectable prepolymer systems (prepolymer A and B) consisting of lactic acid and glycolic acid based polyester star polyols, pentaerythritol (PE) and ethyl lysine diisocyanate (ELDI). This study reports on the formulation and properties of a series of cross linked polyurethanes specifically developed for orthopaedic applications. Prepolymer A was based on PE and ELDI. Polyester polyols (prepolymer B) were based on PE and dl-lactic acid (PEDLLA) or PE and glycolic acid (PEGA) with molecular weights 456 and 453, respectively. Several cross linked porous and non-porous polyurethanes were prepared by mixing and curing prepolymers A and B and their mechanical and thermal properties, in vitro (PBS/37 degrees C/pH 7.4) and in vivo (sheep bi-lateral) degradation evaluated. The effect of incorporating beta-tricalcium phosphate (beta-TCP, 5 microns, 10 wt.%) was also investigated. The cured polymers exhibited high compressive strength (100-190 MPa) and modulus (1600-2300 MPa). beta-TCP improved mechanical properties in PEDLLA based polyurethanes and retarded the onset of in vitro and in vivo degradation. Sheep study results demonstrated that the polymers in both injectable and precured forms did not cause any surgical difficulties or any adverse tissue response. Evidence of new bone growth and the gradual degradation of the polymers were observed with increased implant time up to 6 months.