Improved outcomes in patients with positive metal sensitivity following revision total knee arthroplasty.

BACKGROUND: Metal sensitivity as a cause for painful joint replacement has become increasingly prevalent; however, there is a lack of reported clinical outcome data from total knee arthroplasty patients with metal allergies. The purpose of this study was to determine whether patients presenting with a painful total knee arthroplasty with a positive metal sensitivity have improved outcomes following revision to a hypoallergenic implant. METHODS: A retrospective review was conducted for patients that underwent a revision total knee arthroplasty after metal sensitivity testing over a 3-year period from January 1, 2015, to December 31, 2017. Based on the results of sensitivity testing, patients underwent revision total knee arthroplasty to a hypoallergenic component or a standard component. Following revision, patients returned to the clinic at an interval of 6 weeks, 5 months, and 12 months for functional, pain, and satisfaction assessment. Outcomes were compared within and between sensitivity groups. RESULTS: Of the included patients, 78.3% (39/46) were positive for metal sensitivity. The most common metal sensitivity was to nickel (79.5%, 32/39). Both non-reactive and reactive patients significantly improved in range of motion after revision arthroplasty. The reactive group saw a 37.8% decrease in pain at 6 weeks post-revision (p < 0.001) Whereas, the non-reactive group only saw a moderate, non-significant improvement in pain reduction at 6 weeks post-revision (27.0%; p = 0.29). Frequency of pain experienced did not vary significantly between groups. Maximum metal lymphocyte transformation test (LTT) sensitivity score did not correlate with pain level at the time of revision (R2 = 0.02, p = 0.38) or percent improvement after revision (R2 = 0.001, p = 0.81). Overall, all patients reported being very satisfied after revision total knee arthroplasty; there was no difference between positive and negative sensitivity groups (W = 62, p = 0.89). CONCLUSIONS: Patients presenting with a painful knee arthroplasty and positive metal LTT have improved pain scores, walking function, and range of motion following revision to a hypoallergenic component. This study also provides a treatment algorithm for patients presenting with a painful knee replacement, in order to provide effective and timely diagnosis and management.

Femoral Nerve Block vs Periarticular Bupivacaine Liposome Injection After Primary Total Knee Arthroplasty: Effect on Patient Outcomes.

CONTEXT: Patients receiving femoral nerve blocks for total knee arthroplasty (TKA) have been shown to have a high incidence of postoperative falls, which has been attributed to weakening of the quadriceps muscles. Local injection of analgesic medication that allows for full motor function of the quadriceps and, therefore, better progress through inpatient physical therapy and decreased hospital stay, has been suggested as an option for postoperative pain relief. OBJECTIVE: To compare the number of inpatient physical therapy sessions and hospital days needed in patients receiving periarticular injection of extended-release bupivacaine liposome vs femoral nerve block after TKA. METHODS: Data were retrospectively reviewed from the records of patients who underwent bilateral primary TKA, in which femoral nerve block was administered at the first operation and periarticular injection of an extended-release bupivacaine liposome mixture at the second operation. An average of 2.3 years had passed between the 2 procedures. The number of inpatient physical therapy sessions and hospital days needed were compared between both procedures for each patient. RESULTS: Sixteen patients (14 women) were included in the study, with a mean (SD) age of 63.8 (6.7) years. Compared with femoral nerve block, periarticular injection of analgesic medication resulted in fewer inpatient physical therapy sessions (femoral nerve block: mean [SD], 3.5 [1.3] sessions; periarticular injection: mean [SD], 2.3 [1.0] sessions; P=.002) and fewer hospital days (femoral nerve block: mean [SD], 1.9 [0.6] days; periarticular injection: mean [SD], 1.5 [0.6] days; P<.032). CONCLUSION: Compared with femoral nerve block, periarticular injection of analgesia was found to quicken postoperative recovery in patients hospitalized for TKA. The use of periarticular injections in patients undergoing TKA could yield substantial cost savings given the high frequency of this procedure.

Comparison Between Liposomal Bupivacaine and Femoral Nerve Block in Patients Undergoing Primary Total Knee Arthroplasty.

This study sought to evaluate opioid consumption, hospitalization costs, and length of stay when surgical site periarticular infiltration of liposomal bupivacaine is used after total knee arthroplasty (TKA). Sixty-six consecutive primary TKA cases performed with a single-injection femoral nerve block before this date were compared with 59 consecutive TKA cases performed with the liposomal bupivacaine cocktail after this date. The mean amount of postsurgical opioids consumed was 199 mg versus 121 mg (p = .075), the average hospitalization cost was $28,546 versus $26,472 (p < .001), and the average length of stay was 2.05 days versus 1.58 days (p < .001) in the femoral nerve block versus liposomal bupivacaine group, respectively. There were no significant demographic differences between the two groups. Liposomal bupivacaine infiltration before primary wound closure may be an effective means in lowering hospitalization costs, decreasing length of stay, and decreasing postsurgical opioid consumption after TKA.

Immediate weight bearing after cementless total hip arthroplasty.

This study analyzed 399 Balance femoral stems to determine whether immediate full weight bearing following total hip arthroplasty affected radiographic osseointegration. Postoperatively, all patients were permitted unlimited weight bearing. Findings demonstrated osseointegration was successful in 99.5% of femoral components. Of these, 0.5% subsided in the first 6 postoperative weeks and then osseointegrated; 0.5% failed to osseointegrate. Patients with Dorr C bone had a significantly increased rate of subsidence (P=.006). These findings indicate the Balance stem reliably osseointegrates without subsidence in patients with Dorr A or B bone, despite immediate full weight bearing.

Somatosensory evoked potential monitoring during anterior cervical discectomy and fusion.

STUDY DESIGN: A retrospective, multicenter clinical review was conducted. OBJECTIVE: To examine our experience using somatosensory evoked potential (SSEP) monitoring during anterior cervical discectomy and fusion (ACDF) to determine if monitoring of the spinal cord with SSEPs was helpful in identifying reversible causes of neurologic impairment while performing the procedure. SUMMARY OF BACKGROUND DATA: Recent studies have strongly supported the use of SSEP monitoring during complicated and upper-cervical spine surgery. METHODS: The complete medical records of 163 patients who underwent ACDF, and who were monitored with SSEPs during the procedure between 1995 and 2002 were retrospectively reviewed. A single observer who was uninvolved with patient care abstracted these medical records. Demographic data, length of symptoms, workers' compensation status, primary diagnosis, preoperative neurologic status, number of levels fused, bone graft type, implants used, SSEP findings, postoperative neurologic status, complications, and recovery from complications were recorded. Final neurologic status was determined through phone contact with patients or outpatient charts of patients who could not be contacted personally. RESULTS: There were 3 false positive (1.8%) intraoperative SSEP findings in which SSEP changes intraoperatively did not reflect a neurologic deterioration after surgery. There was 1 false negative (0.6%) in which a new neurologic deficit occurred after surgery, despite no change in SSEP amplitudes during the operation. There were 2 true negatives (1.2%) in which SSEP monitoring showed a preexisting neurologic deficit, which did not change during the operation. CONCLUSION: In no instance were positive SSEP findings clinically useful in alerting the surgeon to potential intraoperative complications. Intraoperative SSEP monitoring is not helpful to the surgeon when performing routine ACDF. Additionally, ACDF is a safe procedure with a low rate of neurologic complications.