Faculty Bibliography

The one-bone forearm procedure can be a successful salvage option for forearm stability in selected patients and is indicated if instability and bone loss are irreparable by other means. We report a case of a dysfunctional arm secondary to radical debridement of the ulna after osteomyelitis treated successfully with a one-bone forearm procedure and followed up for 8 years

Patellofemoral complications, instability, and tibial polyethylene wear after total knee arthroplasty (TKA) resulting from malrotation of the tibial or femoral components (or both) may be difficult to diagnose based on physical examination and standard knee radiographs. The preoperative assessment of implant rotational alignment is critical in planning treatment because the femoral or tibial component (or both) may need to be revised if malpositioned. The purpose of this study was to ascertain the accuracy of computed tomography (CT) scan for determining rotational alignment of femoral and tibial components in TKA. TKA components were inserted in human cadaver specimens at neutral and 5 degrees of external or internal rotation. For each position, the amount of rotation, determined from digital photographs, was compared with CT scan. The correlation coefficient between these two values averaged 0.87, which was significant at P < .05. The CT scan protocol described in this study can be applied clinically to patients with patellofemoral complaints to confirm or rule out the presence of component malrotation

Schuhli locking nuts can be used in poor quality cortical bone to enhance fixation stability as an alternative to cement augmented screws. This study compared the fixation strength and stability of plate constructs using Schuhli locking nuts with standard screws and cement augmented screws for fixation of simulated humeral shaft fractures in a test model with osteoporosis. The constructs were tested in axial compression, 4-point bending, and torsion to determine fixation stability. The humeri were cycled in torsion (4.5 Nm) for 1000 cycles to simulate upper extremity use during the early postoperative period and retested for stability. The Schuhli locking nuts and cement augmented screws had significantly greater fixation stability than the standard screws before (range, 6-14 times greater) and after cycling in torsional loading (range, 3-3.6 times greater). Although cement augmented screws and Schuhli augmentation showed increased fixation stability compared with the standard screws in axial and 4-point bending before cycling (range, 1.3-1.4 times greater), this was not significant. Compared with Schuhli fixation, cement augmented screws showed no significant difference in fixation stability in all loading modes before and after cycling. Schuhli locking nuts offer the stability of cement augmentation while avoiding its potential adverse effects on fracture healing with extravasation and thermal necrosis

BACKGROUND: Treatment of thromboembolism with intravenous heparin therapy in the early postoperative period after total joint arthroplasty has been associated with a high rate of complications. The purpose of the present study was to compare the rate of bleeding complications in a group of patients who required intravenous heparin therapy for the treatment of thromboembolism after total hip or knee arthroplasty with the rate in a control group of patients who received only prophylactic anticoagulation. METHODS: The postoperative courses of forty-four consecutive patients who were managed with intravenous administration of heparin and oral administration of warfarin for the treatment of a thromboembolic event following unilateral total hip or knee arthroplasty were compared with those of a control group of 376 consecutive patients who had these same procedures but did not have a thromboembolic complication. The patients in the control group were managed with prophylactic anticoagulation with use of enoxaparin. Sixty-eight percent (thirty) of the forty-four patients in the heparin group received the initial dose of heparin on or before the fourth postoperative day, and 82 percent (thirty-six) received an initial bolus of 5000 units of heparin at the initiation of therapy. RESULTS: The rate of bleeding complications was 9 percent (four of forty-four) in the heparin group, compared with 6 percent (twenty-three of 376) in the control group (p = 0.44). The mean transfusion requirement in the heparin group (1.8 units of packed red blood cells) was significantly greater than that in the control group (0.8 unit) (p < 0.0001). Three of the four patients who had a bleeding complication while receiving heparin and warfarin had coagulation parameters that were substantially higher than recommended levels. The mean duration of hospitalization in the heparin group (fifteen days) was significantly longer than that in the control group (seven days) (p < 0.0001). CONCLUSIONS: The results of the present study suggest that the use of intravenous heparin therapy for the treatment of thromboembolism in the early postoperative period after total joint arthroplasty is associated with a rate of bleeding complications that is similar to that associated with the use of prophylactic anticoagulation with use of enoxaparin alone. One should expect an increased transfusion requirement and a longer duration of hospitalization for patients who require intravenous heparin therapy for the treatment of a thromboembolic event

BACKGROUND: A comminuted, intra-articular distal femur fracture was surgically treated by the authors with a locked, double-plating technique because fixation stability could not be initially achieved by using a standard double-plating technique. The purpose of this study was to determine biomechanically whether a locked double-plate construct would enhance fixation stability compared with a nonlocked double-plate construct. METHODS: Six matched pairs of mildly osteopenic femurs were selected and all had a reproducible intra-articular fracture pattern created. Each pair underwent fixation with either a double-plating construct or a locked, double-plating construct that was randomly assigned. The instrumented femurs were then mechanically tested in several loading modes to determine fixation stability. After initial testing, specimens were cyclically loaded and retested for stability. RESULTS: The locked, double-plating construct provided significantly greater fixation stability than the standard double-plating construct in precycling and postcycling biomechanical testing. CONCLUSION: The technique described is particularly applicable for severely comminuted fractures of the distal femur and fractures in osteopenic bone with poor screw purchase. It offers a simple alternative for enhancing fixation stability, which avoids the potential complications of methylmethacrylate-enhanced screw fixation

No studies have demonstrated a direct relationship between pregnancy and rib fracture. A case of spontaneous rib fracture in the third trimester presents the opportunity to examine factors unique to pregnancy that may predispose the patient to stress fractures of the lower ribs. A 28-year old woman in week 31 of her pregnancy presented with the chief complaint of acute onset of right upper quadrant pain. A chest radiograph demonstrated a minimally displaced fracture of the right 10th rib. During pregnancy, the enlarging uterus causes certain opposing muscular forces to act on the ribs, making them more susceptible to fracture after minimal trauma or after repeated stresses such as a chronic cough

High rates of aseptic loosening have been reported for microstructured hydroxyapatite-coated acetabular components. A macrostructured component surface (arc-deposition) not only improves resistance to shear forces experienced by the acetabular component and increases initial stability, but also provides channels for bone ingrowth. The purpose of this investigation was to radiographically compare a series of grit-blasted (microstructured) and arc-deposited (macrostructured) hydroxyapatite-coated acetabular components. A minimum 4-year retrospective radiographic analysis of acetabular components was performed on a total of 50 total hip arthroplasties. At 4 years, arc-deposited components were associated with fewer radiolucent lines in all Charnley zones, particularly Charnley zone III. While the 4-year results for arc-deposited hydroxyapatite acetabular components are superior to their microstructured predecessors, long-term results are still unknown

A case of arthroscopic removal of a bullet fragment from the subtalar joint and the calcaneus is presented. The bullet fragments impinged on the fibula, limiting eversion and causing pain. The fragments were removed both arthroscopically and through open incision. The patient noted complete relief of pain and improved range of motion within 1 week, and complete recovery soon thereafter

A retrospective clinical and radiographic analysis was performed on 58 patients (60 hips; mean age at time of surgery, 45.2 years) at a minimum of 10-year follow-up (mean, 12.7 years) after total hip replacement using a ceramic-on-ceramic hearing total hip implant (Autophor, Smith and Nephew, Memphis, TN). Mean wear rate at final follow-up was 0.21 mim, averaging 0.016 mm/y. There were no cases of periprosthetic osteolysis in the acetabuulum or femur. For the unrevised components, there were 3 (5%) cases of protrusio acetabuli and 4 (7%) cases of acetabular component loosening. On the femoral side, 78.3% had distal pedestal formation, and 83% had greater than 2 mm implant-bone radiolucencies in more than 5 Gruen zones as a result of gross motion of the stem. Despite radiographic evidence of implant loosening, this hard bearing articulation functioned well in vivo for more than 12 years with remarkably low wear--approximately one tenth the rate reported for metal-on-polyethylene total hip bearings

A biomechanical cadaver study was performed to compare the strength and stability of three cannulated cancellous lag screws with a sliding hip screw for fixation of a vertically oriented fracture of the femoral neck (Pauwels Type III). Using eight matched pairs of human cadaveric femurs, vertically oriented femoral neck osteotomies were created, reduced, and randomized to one of the two fixation methods. The constructs were tested with incremental axial loading from 100 N to 1200 N and cyclical loading at 1000 N for 10,000 cycles; fracture displacements and ultimate load to failure were determined. The specimens stabilized using a sliding hip screw showed less inferior femoral head displacement, less shearing displacement at the osteotomy site, and a much greater load to failure than did those stabilized with multiple cancellous lag screws. These results support the use of a sliding hip screw for treatment of vertically oriented fractures of the femoral neck.