Brian T. Palumbo

Humeral shaft fractures: a review

Summary Humeral shaft fractures are common orthopaedicinjuries that can often be managed nonoperatively withhigh union rates and excellent results as the generaloutcome. Specific indications exist for operativemanagement and include polytrauma patients, openfractures, certain fracture patterns, and failure to main-tain an acceptable closed reduction. Plate fixation ofhumeral shaft fractures has historically been consideredthe gold standard of operative management based ona lower complication rate; however, newer intra-medullary devices may prove as effective in fracturemanagement pending future prospective analysis.Although radial nerve palsy remains a vexing andcommon comorbidity of humeral shaft fracturemanagement, recovery can be expected in mostcircumstances. Disclaimer The authors, their immediate families, and any researchfoundations with which they are affiliated have notreceived any financial payments or other benefits fromany commercial entity related to the subject of thisarticle.

Initial Experience of the Journey-Deuce Bicompartmental Knee Prosthesis A Review of 36 Cases

We evaluated the effectiveness of a novel bicompartmental knee arthroplasty prosthesis for the treatment of degenerative disease affecting the medial and patellofemoral compartments. The study included 36 knees in 32 patients with a mean follow-up of 21 months. The mean Knee Society functional survey and Western Ontario McMaster Osteoarthritic Index Survey scores were 65.4 and 75.8, respectively. Thirty-one percent of patients were unsatisfied with the surgery, and 53% stated that they would not repeat the surgery. We report an overall survival rate of 86% with one catastrophically failed tibial baseplate. We conclude that this prosthesis provides inconsistent pain relief and unacceptable functional results for bicompartmental arthritis. Short-term survival of this prosthesis was unacceptably low, and therefore, we no longer implant it at our institution.

Advances in Segmental Endoprosthetic Reconstruction for Extremity Tumors: A Review of Contemporary Designs and Techniques

BACKGROUND Improved understanding and advances in treatment regimens have led to increased longevity among patients diagnosed with extremity soft tissue sarcomas. Limb salvage techniques and implants have improved and continue to evolve to accommodate the increasing demands and survival of these patients. METHODS The current report is a review of the literature for recent advancements in techniques, implant design, and outcomes in the field of limb salvage therapy using segmental megaprostheses for the treatment of extremity sarcomas. We report on our experience in this field utilizing a classification system of failure mechanisms to outline to discuss current controversies in management. RESULTS Five mechanisms of failure have been identified: soft-tissue failure, aseptic loosening, structural failure, infection, and tumor progression. Infection was the most common mode of failure in our series, accounting for 34% of cases. Soft-tissue failure occurred most commonly in the joints that depend heavily on periarticular muscles and ligaments for stability due to their high degree of functional range of motion. We observed a 28% soft-tissue failure rate about the shoulder and hip, aseptic loosening accounted for 19% of implant failures, and structural failure was seen in 17% of cases. Seventeen percent of cases failed due to tumor progression, an etiology that is defined by biological factors, surgical technique, and adjuvant therapies. CONCLUSIONS Surgical techniques and megaprosthesis designs are constantly changing in order to meet the challenge of increasing functional demands and longevity in this unique patient population. A classification system defined by treatment failure etiologies provides the framework for discussion of current controversies in limb salvage therapy as well as a guide for advancement and potential solutions in this challenging arena.

Results of revision total hip arthroplasty with modular, titanium-tapered femoral stems in severe proximal metaphyseal and diaphyseal bone loss.

Evidence supporting modular, tapered stems for severe proximal metaphyseal and diaphyseal bone loss is limited. We report our clinical experience with its use for severely deficient femurs. Of 211 revision total hip arthroplasties (THAs), 18 tapered, modular titanium stems were implanted in Paprosky type III and IV femurs. Clinical data were reviewed for function, stability, structural failure and revision surgery at a mean follow-up of 4.5years. The overall survival rate was 94%. One required revision due to infection and subsidence. The mean subsidence was 3.5mm and the mean pre- and post-operative Harris Hip score was 56 and 79, respectively. In surviving cases, patients achieved satisfactory function and there were no mechanical failures. Modular, tapered stems demonstrated acceptable outcomes for management of severe proximal metaphyseal and diaphyseal defects.

Biomechanical analysis of impending femoral neck fractures: the role of percutaneous cement augmentation for osteolytic lesions

BACKGROUND Management of impending pathologic femoral neck fractures includes internal fixation, arthroplasty and megaprostheses. The study aim was to determine the augmentative effect of cement injection for minimally invasive treatment of femoral neck lesions. METHODS Twenty-seven cadaveric femora received a simulated osteolytic lesion previously shown to decrease the femurs failure load by 50%. Specimens were allocated to three groups of nine and loaded to failure in simulated single-leg stance: (1) percutaneous cementation + internal fixation (PCIF); (2) percutaneous cementation (PC); and (3) internal fixation (IF). Lesion-only and augmented finite element models were virtually loaded and stresses were queried adjacent to the lesion. FINDINGS PCIF resulted in the largest failure load though the increase was not significantly greater than the PC or IF groups. Inspection of the PC and PCIF specimens indicated that the generation of a cement column that spanned the superior and inferior cortices of the femoral neck increased failure loads significantly. Finite element analysis indicated that IF and PCIF constructs decreased the stress adjacent to the lesion to intact femur levels. Cementation without superior-to-inferior femoral neck cortical contact did not restore proximal femoral stress toward the intact condition. INTERPRETATION Internal fixation alone and internal fixation with or without cementation produce similar levels of mechanical augmentation in femora containing a high-risk lesion of impending fracture. A cement injection technique that produces a cement column contacting the superior and inferior femoral neck cortices confers the highest degree of biomechanical stability, should percutaneous cementation alone be performed.

Use of extendable prostheses: a limb-salvaging alternative for patients with malignant bone tumors

Children with primary bone tumors require radical surgical procedures and complex reconstructions. In addition to adequate disease control, the surgeon has to address the injured growth plate and consequent limb length inequality. Extendable prostheses constitute an alternative to other limb-salvaging techniques. Since the first description of the device three decades ago, several changes in materials, design and indications have been a matter of constant debate. The indications and results of this prosthesis will be reviewed and an expert commentary regarding the current and future trends of the device will be presented.

Biomechanical model of a high risk impending pathologic fracture of the femur: Lesion creation based on clinically implemented scoring systems

BACKGROUND Multiple classifications combine objective and subjective measures to predict fracture risk through a metastatic lesion. In our literature review, no studies have attempted to validate this predicted fracture risk from a biomechanical perspective. The study goal was to evaluate proximal femur strength after creating osteolytic defects. We report a standardized technique to re-create a metastatic lesion. METHODS Eight femoral matched pairs were procured and a standardized technique was used to create an osteolytic femoral neck defect in one femur with the contralateral specimen serving as the control. Femurs were loaded to failure in a material testing machine at 2 mm/s. Failure load (N) and location of failure were documented. 3D finite element (FE) femur models with and without the lesions were developed to predict von Mises stresses in the femoral neck and compare between the two models. FINDINGS Femurs containing the osteolytic defect failed at significantly lower loads than the intact specimens in a reproducible manner (intact: 10.69 kN (3.09 SD); lesion: 5.56 kN (2.03 SD), p<0.001). The average reduction in failure load was 48%, and the fracture pattern was consistent in all specimens. FE model comparison similarly predicted significantly higher von Mises stress at the lesion. INTERPRETATION Our methods and pathologic fracture model represent the clinical parameters of metastatic bone disease and suggest a significant reduction in structural integrity of the lesion-containing femur. Prophylactic surgical fixation may be warranted clinically to reduce the risk of pathologic fracture. Our model technique is reproducible and may be used in future studies.

Purse-string capsule repair to reduce proximal femoral arthroplasty dislocation for tumor-a novel technique with results .

Hip joint dislocation is the most common complication after proximal femoral arthroplasty with a large endoprosthesis. Average dislocation rates are around 15%. In an attempt to decrease dislocations after proximal femoral arthroplasty for tumor resections, we devised a novel closure of the hip capsule. This technique uses a 3-mm cottony Dacron suture placed about the hip capsule in a circumferential, purse-string manner. Thirty-nine patients received hip hemiarthroplasty with purse-string capsular closure. Seven patients were lost to follow-up, leaving 36 patients available for analysis. One patient dislocated (2.8%). We believe this technique is useful in preventing dislocation in patients undergoing proximal femoral arthroplasty for oncologic disease.

Femoral Component Incarceration at the Distal Slot

Femoral components with distal coronal slots were introduced to decrease the stiffness mismatch of the femoral diaphysis and stem. We present 2 cases in which the stem of an S-ROM (DePuy, Warsaw, Ind) endoprosthesis was incarcerated in the diaphysis of the femur by bone growth through the distal slot. In both cases, this finding was discovered intraoperatively, following multiple unsuccessful attempts at stem extraction. We recommend performing a trans femoral cortical window at the distal slot, which provides adequate visualization of the stem and allows for resection of the anterior tine and osseous bar. Early recognition of this potential pitfall may decrease the risk for iatrogenic femur fracture, prolonged operative time, extended anesthetic exposure, and greater blood loss.

Computer navigation and distal femoral reconstruction in the oncologic patient

OBJECTIVES As adjuvant treatments for musculoskeletal malignancies improve expectations of preserved function increase. We questioned whether computer navigation for distal femoral reconstruction would improve outcomes. METHODS Twenty oncology patients were reviewed after distal femoral reconstruction using navigation. Outcomes included local recurrence, implant revision, patient function, patellofemoral complications and leg-length inequality. RESULTS Implant survivorship was 85% at 26 months. There were no local recurrences and 3 failures for aseptic loosening. Good functional outcomes were observed in remaining cases. CONCLUSION Computer navigation for distal femoral reconstruction resulted in acceptable functional outcomes and implant survivorship. Reduced local recurrence were observed at intermediate follow-up. Level of Evidence: Level IV.