Chad D. Watts

Morbid obesity: a significant risk factor for failure of two-stage revision total knee arthroplasty for infection.

BACKGROUND Obese patients have a higher risk of complications following primary total knee arthroplasty, including periprosthetic joint infection. However, there is a paucity of data concerning the efficacy of two-stage revision arthroplasty in obese patients. METHODS We performed a two-to-one matched cohort study to compare the outcomes of thirty-seven morbidly obese patients (those with a body mass index of ≥ 40 kg/m(2)) who underwent two-stage revision total knee arthroplasty for periprosthetic joint infection following primary total knee arthroplasty with the outcomes of seventy-four non-obese patients (those with a body mass index of <30 kg/m(2)). Groups were matched by sex, age, and date of reimplantation. Outcomes included subsequent revision, reinfection, reoperation, and Knee Society pain and function scores. The minimum follow-up time was five years. RESULTS Morbidly obese patients had a significantly increased risk for revision surgery (32% compared with 11%; p < 0.01), reinfection (22% compared with 4%; p < 0.01), and reoperation (51% compared with 16%; p < 0.01). Implant survival rates were 80% for the morbidly obese group and 97% for the non-obese group at five years and 55% for the morbidly obese group and 82% for the non-obese group at ten years. Knee Society pain scores improved significantly following surgery in both groups; the mean scores (and standard deviation) were 50 ± 5 points for the morbidly obese group and 55 ± 2 points for the non-obese group (p = 0.06) preoperatively, 74 ± 5 points for the morbidly obese group and 89 ± 2 points for the non-obese group (p < 0.0001) at two years, 72 ± 6 points for the morbidly obese group and 88 ± 3 points for the non-obese group (p < 0.0001) at five years, and 56 ± 9 points for the morbidly obese group and 84 ± 3 points for the non-obese group (p = 0.01) at ten years. CONCLUSIONS Morbid obesity significantly increased the risk of subsequent revision, reoperation, and reinfection following two-stage revision total knee arthroplasty for infection. In addition, these patients had worse pain relief and overall function at intermediate-term clinical follow-up. Although two-stage revision should remain a standard treatment for chronic periprosthetic joint infection in morbidly obese patients, increased failure rates and poorer outcomes should be anticipated.

Epidemiology of periprosthetic fracture of the femur in 32 644 primary total hip arthroplasties: a 40-year experience

AIM AND METHODS The goals of this study were to define the risk factors, nature, chronology, and treatment strategies adopted for periprosthetic femoral fractures in 32 644 primary total hip arthroplasties (THAs). RESULTS There were 564 intra-operative fractures (1.7%); 529 during uncemented stem placement (3.0%) and 35 during cemented stem placement (0.23%). Intra-operative fractures were more common in females and patients over 65 years (p < 0.001). The majority occurred during placement of the femoral component (60%), and involved the calcar (69%). There were 557 post-operative fractures (20-year probability: 3.5%; 95% confidence interval (CI) 3.2 to 3.9); 335 fractures after placement of an uncemented stem (20-year probability: 7.7%; 95% CI 6.2 to 9.1) and 222 after placement of a cemented stem (20-year probability: 2.1%; 95% CI 1.8 to 2.5). The probability of a post-operative fracture within 30 days after an uncemented stem was ten times higher than a cemented stem. The most common post-operative fracture type was a Vancouver AG (32%; n = 135), with 67% occurring after a fall. In all, 36% (n = 152) were treated with revision arthroplasty. CONCLUSION In summary, intra-operative fractures occur 14 times more often with uncemented stems. Female patients over 65 years of age are at highest risk. Post-operative fractures are also most common with uncemented stems, but are independent of age or gender. Cumulative risk of post-operative periprosthetic femur fracture was 3.5% at 20 years. TAKE HOME MESSAGE Intra-operative fractures occur 14 times more often with uncemented stems, particularly with female patients over 65 years of age, while post-operative fracture risk is independent of age or gender, but still increased with uncemented stems.

Bariatric surgery does not improve outcomes in patients undergoing primary total knee arthroplasty

Bariatric surgery has been advocated as a means of reducing body mass index (BMI) and the risks associated with total knee arthroplasty (TKA). However, this has not been proved clinically. In order to determine the impact of bariatric surgery on the outcome of TKA, we identified a cohort of 91 TKAs that were performed in patients who had undergone bariatric surgery (bariatric cohort). These were matched with two separate cohorts of patients who had not undergone bariatric surgery. One was matched 1:1 with those with a higher pre-bariatric BMI (high BMI group), and the other was matched 1:2 based on those with a lower pre-TKA BMI (low BMI group). In the bariatric group, the mean BMI before bariatric surgery was 51.1 kg/m(2) (37 to 72), which improved to 37.3 kg/m(2) (24 to 59) at the time of TKA. Patients in the bariatric group had a higher risk of, and worse survival free of, re-operation (hazard ratio (HR) 2.6; 95% confidence interval (CI) 1.2 to 6.2; p = 0.02) compared with the high BMI group. Furthermore, the bariatric group had a higher risk of, and worse survival free of re-operation (HR 2.4; 95% CI 1.2 to 3.3; p = 0.2) and revision (HR 2.2; 95% CI 1.1 to 6.5; p = 0.04) compared with the low BMI group. While bariatric surgery reduced the BMI in our patients, more analysis is needed before recommending bariatric surgery before TKA in obese patients.

Ulnar Collateral Ligament Reconstruction With Gracilis Tendon in Athletes With Intraligamentous Bony Excision Technique and Results

Background: Ulnar collateral ligament (UCL) reconstruction is frequently performed in throwing athletes, but outcomes of UCL reconstruction requiring excision of bone, either within the substance of or replacing the UCL, have not been studied. Hypothesis: Clinical outcome for throwing athletes after UCL reconstruction with gracilis tendon will be less favorable for patients requiring concurrent excision of bone from within the substance of the UCL than for patients with no bone excision within, or replacing, the ligamentous anatomy. Study Design: Cohort Study; Level of evidence, 3. Methods: One hundred twenty pitchers of competitive levels between high school and major league who underwent UCL reconstruction using contralateral gracilis autografts completed a phone survey, and their medical charts were reviewed. Follow-up was a minimum of 2 years. Among the 120 patients, 42 (35%) had bone within, or replacing, the substance of the native UCL (bony group), and 78 (65%) had no bony abnormalities (nonbony group). The latter group of 78 underwent UCL reconstruction using gracilis tendon graft due to the absence of a palmaris longus tendon. Clinical outcomes were compared between the 2 study groups using t tests and χ2 analyses. Results: There were no statistical differences regarding time to return to throwing, time to return to competition, postoperative complications, or need for additional surgeries. The percentage of patients who returned to the same or higher level was higher in the nonbony group (91%) than in the bony group (81%), but this trend was not statistically significant (P = .083), likely due to a relatively small sample size. Changes in self-reported pitch control were different (P = .029) between the 2 groups, with a greater percentage of pitchers experiencing decreased control in the bony group. Conclusion: The presence of bone concomitant with UCL damage can lead to pitch control problems after UCL reconstruction and may also decrease the chance of return to play.

Insulin Dependence Increases the Risk of Failure After Total Knee Arthroplasty in Morbidly Obese Patients

UNLABELLED The aims of this study were to compare the outcomes between nondiabetic (n=1284), type II diabetic (n=530), and insulin-dependent type II diabetic (n=164) morbidly obese (body mass index ≥40 kg/m(2)) patients undergoing primary total knee arthroplasty at 6-year follow-up. Patients with type II diabetes mellitus (DM) had similar outcomes when compared with non-DM patients. However, patients with insulin dependence had an increased risk of reoperation (hazard ratio [HR], 1.8; P=.005), revision (HR, 2; P=.02), and periprosthetic joint infection (HR, 2.1; P=.03), as well as decreased 10-year implant survivorship (84% vs 92%; P=.01) when compared to non-DM patients. Prospective studies should further evaluate outcomes and optimization measures within this population. LEVEL OF EVIDENCE Level III-prognostic study.

Open Versus Arthroscopic Reduction for Tibial Eminence Fracture Fixation in Children.

Background: Stiffness is a common complication following surgically treated tibial eminence fractures. Fractures can be addressed with either open reduction and internal fixation (ORIF) or arthroscopic reduction and internal fixation (ARIF). We sought to evaluate the effects of surgical approach and other modifiable perioperative factors on postoperative arthrofibrosis. We hypothesized that ARIF would result in a lower risk of arthrofibrosis. Methods: We retrospectively reviewed the records of all patients aged 18 years and below treated for tibial eminence fractures at our institution from 1998 to 2014. All patients were treated by either pediatric or sports fellowship-trained orthopaedic surgeons and followed until radiographic union and return of range of motion or treatment for arthrofibrosis (minimum 3 mo). Results: Thirty-one patients were included in our analysis, 13 in the ORIF group and 18 in the ARIF group. The groups were similar in regards to sex, age, fracture type, fixation method, and length of postoperative immobilization. However, when compared with the ORIF group, patients in the ARIF group had significantly longer time from injury to surgery (4.2 vs. 6.3 d, P=0.03), operative time (98 vs. 141 min, P=0.02), and tourniquet time (76 vs. 100 min, P=0.006). In the ARIF group, 6 (33.3%) patients acquired arthrofibrosis compared with only 1 (7.7%) patient in the ORIF group. Delaying surgery ≥7 days from injury [hazard ratio (HR)=4.7, P=0.04] and operative time ≥120 minutes (HR=9.1, P=0.03) were risk factors for arthrofibrosis. ARIF was a risk factor in univariate (HR=4.0, P=0.04), but not in multivariate (1.4, P=0.77) analysis. Conclusions: Delayed surgery (≥7 d from injury) and prolonged operative times (≥120 min) were significant risk factors for arthrofibrosis. Although ARIF was not an independent risk factor, these patients were exposed to markedly longer wait times before surgery and operative times when compared with ORIF patients. ORIF is a reasonable option for treatment of displaced tibial eminence fractures. Surgeons should approach tibial eminence fractures with whichever mode they can accomplish with higher efficiency. Level of Evidence: Level III—therapeutic study.

Prior bariatric surgery may decrease the rate of re-operation and revision following total hip arthroplasty

AIMS We compared the outcome of total hip arthroplasty (THA) in obese patients who previously underwent bariatric surgery and those who did not, in a matched cohort study. PATIENTS AND METHODS There were 47 THAs in the bariatric group (42 patients), and 94 THAs in the comparison group (92 patients). The mean age of the patients was 57 years in both groups (24 to 79) and 57% of the patients in both groups were women. The mean time between bariatric surgery and THA was five years (four months to 12 years) in the bariatric group. The mean follow-up after THA was three years (2 to 9). RESULTS The mean BMI improved from 49.7 kg/m(2) (35 to 75) prior to bariatric surgery to 35.3 kg/m(2) (21 to 49) at the time of THA (p < 0.001). Patients in the comparison group had an increased risk of re-operation (Hazard Ratio (HR) 3.2; 95% confidence intervals (CI) 1.3 to 9.5, p = 0.01) and revision (HR 5.4; 95% CI 1.5 to 34.5, p = 0.01) when compared with the bariatric group. CONCLUSION Patients had a dramatic improvement in BMI after bariatric surgery and those with prior bariatric surgery had a lower risk of re-operation and revision in the short- and mid-term after a subsequent THA. Larger prospective studies are required before it can be concluded that this extra surgery should be advised in these patients. Cite this article: Bone Joint J 2016;98-B:1180-4.

Medial Tibial Stress Shielding: A Limitation of Cobalt Chromium Tibial Baseplates.

BACKGROUND Stress shielding is a well-recognized complication associated with total knee arthroplasty. However, this phenomenon has not been thoroughly described. Specifically, no study to our knowledge has evaluated the radiographic impact of utilizing various tibial component compositions on tibial stress shielding. METHODS We retrospectively reviewed 3 cohorts of 50 patients that had a preoperative varus deformity and were implanted with a titanium, cobalt chromium (CoCr), or an all polyethylene tibial implant. A radiographic comparative analysis was performed to evaluate the amount of medial tibial bone loss in each cohort. In addition, a clinical outcomes analysis was performed on the 3 cohorts. RESULTS The CoCr was noted to have a statistically significant increase in medial tibial bone loss compared with the other 2 cohorts. The all polyethylene cohort had a statistically significantly higher final Knee Society Score and was associated with the least amount of stress shielding. CONCLUSION The CoCr tray is the most rigid of 3 implants that were compared in this study. Interestingly, this cohort had the highest amount of medial tibial bone loss. In addition, 1 patient in the CoCr cohort had medial soft tissue irritation which was attributed to a prominent medial tibial tray which required revision surgery to mitigate the symptoms.

Single-Anesthetic Versus Staged Bilateral Total Hip Arthroplasty: A Matched Cohort Study.

Background: There is debate regarding the role of single-anesthetic versus staged bilateral total hip arthroplasty (THA) for patients with end-stage bilateral osteoarthritis. Studies have shown that single-anesthetic bilateral THA is associated with systemic complications, but there are limited data comparing patient outcomes in a matched setting of bilateral THA. Methods: We identified 94 patients (188 hips) who underwent single-anesthetic bilateral THA. Fifty-seven percent of the patients were male. Patients had a mean age of 52.2 years and body mass index of 27.1 kg/m2. They were matched 1:1 on the basis of sex, age (±1 year), and year of surgery (±3 years) to a cohort of patients undergoing staged bilateral THA. In the staged group, there was <1 year between procedures (range, 5 days to 10 months). Mean follow-up was 4 years for each group. Results: Patients in the single-anesthetic group experienced shorter total operating room time and length of stay. There was no difference (hazard ratio [HR] = 0.73, p = 0.50) in the overall revision-free survival in patients undergoing single-anesthetic or staged bilateral THA. The risks of reoperation (HR = 0.69, p = 0.40), complications (HR = 0.83, p = 0.48), and mortality (HR = 0.47, p = 0.10) were similar. Single-anesthetic bilateral THA reduced the total cost of care (by 27%, p = 0.0001). Conclusions: In this matched cohort analysis, single-anesthetic bilateral THA was not associated with an increased risk of revision, reoperation, or postoperative complications, while decreasing cost. In our experience, single-anesthetic bilateral THA is a safe procedure that, for certain patients, offers an excellent means to deal with bilateral hip osteoarthritis. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Anatomic Hip Center Decreases Aseptic Loosening Rates After Total Hip Arthroplasty with Cement in Patients with Crowe Type-ii Dysplasia: A Concise Follow-up Report at a Mean of Thirty-six Years*

UNLABELLED We previously reported the two to twenty-two-year results of 145 total hip arthroplasties (THAs) with cement performed from 1969 to 1980 in 117 patients with Crowe type-II dysplasia. The purpose of the present study was to update the long-term effects of a nonanatomic hip center on component loosening and aseptic revision in this cohort. Forty-nine patients (sixty hips) were alive at a mean of thirty-six years. The overall cumulative incidence of aseptic revision at thirty-five years was 32% for acetabular cups and 21% for femoral stems. Acetabular loosening was less likely with a hip center placed within the true acetabular region (TAR), <15 mm superior to the approximate femoral head center (AFHC), <35 mm superior to the interteardrop line (ITL), or within zone 1. Femoral loosening and revision were less likely with the hip center placed <35 mm superior to the ITL and within zone 1. An anatomic hip center was associated with significantly lower loosening and aseptic revision rates for both acetabular and femoral components. The current study supports the placement of acetabular components in an anatomic position to promote long-term durability after THA with cement. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.