Faculty Bibliography

Component malalignment can be associated with pain following total knee replacement (TKR). Using MRI, we reviewed 50 patients with painful TKRs and compared them with a group of 16 asymptomatic controls to determine the feasibility of using MRI in evaluating the rotational alignment of the components. Using the additional soft-tissue detail provided by this modality, we also evaluated the extent of synovitis within these two groups. Angular measurements were based on the femoral transepicondylar axis and tibial tubercle. Between two observers, there was very high interobserver agreement in the measurements of all values. Patients with painful TKRs demonstrated statistically significant relative internal rotation of the femoral component (p = 0.030). There was relative internal rotation of the tibial to femoral component and combined excessive internal rotation of the components in symptomatic knees, although these results were significant only with one of the observers (p = 0.031). There was a statistically significant association between the presence and severity of synovitis and painful TKR (p < 0.001). MRI is an effective modality in evaluating component rotational alignment.

This study examined the effect of patient attributes on expectations before total knee arthroplasty (TKA). A total of 1943 patients completed an Expectations Survey before TKA. Demographics, surgical history, baseline Medical Outcomes Study Short Form 36 (SF-36) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lower Extremity Activity Scale score were obtained. On univariate analysis, expectations (mean score, 77.6) correlated with SF-36 General Health, age, SF-36 Vitality, KOOS Quality-of-Life, and Lower Extremity Activity Scale. Living alone and history of joint arthroplasty were associated with significantly lower expectations, whereas male sex and white race were associated with higher expectations. On multivariate regression analysis, age, living situation, history of joint arthroplasty, SF-36 General Health, and KOOS Quality-of-Life remained significant predictors of expectations. Our results suggest that high, possibly unrealistic, expectations of TKA are common and should be moderated to maintain patient satisfaction.

Tibial insert locking mechanisms are intended to limit interface motion and "backside" wear in modular total knee arthroplasty (TKA). Nevertheless, anterior polyethylene subluxation is occasionally apparent on lateral radiographs after TKA, suggesting locking mechanism failure. We retrospectively identified 10 modular posterior-stabilized implants of a single design that were found to have failure of the locking mechanism at the time of revision surgery for osteolysis. Operative reports were reviewed for the presence of backside wear, and preoperative radiographs were inspected for polyethylene subluxation. All 10 implants demonstrated significant backside wear. Nine had anterior polyethylene subluxation evident on preoperative radiographs. Anterior polyethylene subluxation on the lateral radiograph is a subtle sign of failure of the locking mechanism in this modular posterior-stabilized TKA.

Implants designed for enhanced flexion offer the prospect of improved function after total knee replacement (TKR). Whereas most studies evaluating these implants have focused on the range of knee flexion achieved, this study investigated the quality of function in deep knee flexion. The influences of residual pain and maximum flexion angle on function in deep knee flexion were also examined. Eighty-three patients (100 knees) were prospectively followed for 1 year after TKR with a rotating-platform posterior-stabilized high-flexion prosthesis. Range of motion was measured and Knee Society scores were calculated. A questionnaire evaluated residual knee pain and function in high-flexion activities. Mean Knee Society score was 95, and mean knee flexion was 125°, yet 20% of patients could neither kneel, nor squat, nor sit on their heels. Fifty-seven percent were able to kneel without significant difficulty; 69% were able to squat without significant difficulty; and 46% were able to sit on their heels without significant difficulty. Function in deep flexion correlated with pain scores but did not correlate with knee flexion angles or Knee Society scores. Results 1 year after TKR with a rotating-platform posterior-stabilized high-flexion prosthesis are encouraging, but one in five patients remain significantly limited in high-flexion activities.

To avoid the potential risks of allogeneic transfusion during total hip arthroplasty (THA), the use of preoperative autologous blood donation (PABD) has been utilized. We performed a retrospective chart review of 283 patients undergoing THA that either donated 1 U of autologous blood (188 patients) or did not donate autologous blood before surgery (95 patients) in order to investigate the difference in postoperative transfusion rate (autologous and allogeneic), the incidence of allogeneic transfusion, and the difference in cost of each protocol. In addition, the study compared transfusion rates in patients with and without preoperative anemia (hemoglobin (Hb) ≤ 12.5 g/dL). At 0.75 transfusions per patient versus 0.22 transfusions per patient, the PABD patients had a significantly higher overall transfusion rate. PABD significantly reduced the need for allogeneic blood in anemic patients (Hb ≤ 12.5 g/dL) from 52.6% to 11.8%. PABD did not have the same affect in nonanemic patients (allogeneic transfusion rate 5.7% versus 4.0%). The study demonstrated that nonanemic patients undergoing THA do not benefit from PABD, but it is effective for anemic patients.

PURPOSE: In patients having basal joint arthroplasty, rates of concomitant carpal tunnel syndrome may exceed 43%. Excision of the trapezium during basal joint arthroplasty partially releases the transverse carpal ligament. The objective of this study was to determine whether indirect release of the remaining fibers of the ligament at its insertion on the scaphoid tubercle through the same incision would adequately decompress the carpal canal. This would avoid the morbidity of a second incision. METHODS: We retrospectively reviewed 10 consecutive patients treated over a 2-year period who had concurrent ligament reconstruction, tendon interposition basal joint arthroplasty of the thumb with complete trapezial resection, and indirect carpal tunnel release through a single incision. Self-reported postoperative pain relief was documented. Preoperative and postoperative evaluations of light touch sensibility, Tinel's sign, Phalen's test, median nerve compression test, and Weinstein Enhanced Sensory Test monofilament testing were analyzed. All patients had preoperative electrodiagnostic testing. RESULTS: At mean 12 month follow-up (range, 5-35 months), numbness and paresthesias resolved in all cases: 9 patients had good or excellent pain relief and 1 reported fair pain relief despite transient postoperative reflex sympathetic dystrophy. Tinel's, Phalen's, and median nerve compression tests were each positive in 9 patients preoperatively and 0 patients postoperatively. Diminished light touch sensibility was present in 7 preoperatively and 1 postoperatively. WEST monofilament thresholds improved postoperatively in 8 patients. These improvements were statistically significant. One patient had postoperative nerve conduction studies performed to evaluate an ulnar nerve lesion at the elbow; the preoperative median nerve abnormalities had normalized. CONCLUSIONS: Carpal tunnel syndrome can be successfully managed with indirect release of the transverse carpal ligament during basal joint arthroplasty, thus avoiding a second incision, reducing operating time, and potentially reducing the possibility of perineural adhesions, recurrent motor branch injury, palmar cutaneous nerve damage, weakness, stiffness, and pillar pain. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV

Total hip arthroplasty is characterized by significant blood loss. The principal aim of blood management in joint replacement surgery is to minimize both the risks associated with surgical blood loss and the risks associated with allogenic blood transfusion. In the 1980s, the AIDS epidemic triggered the development of a variety of innovative approaches to conserving blood and reducing the need for allogenic transfusion to replace surgical blood loss. Subsequently, the safety of the blood supply was dramatically improved, changes in surgical technique led to decreased surgical blood loss, and changes in transfusion thresholds made the need for transfusion less common. The review re-examines the options available for the management of blood loss in total joint replacement and defines parameters that can be used preoperatively to predict which patients are likely to benefit from these interventions, given the clinical realities of the 21st century.