Richard A. Berger’s research while affiliated with Rush University Medical Center and other places

The purpose of this study was to evaluate outcomes of late manipulation under anesthesia (MUA) for stiffness performed from ≥12 weeks to more than a year after primary total knee arthroplasty (TKA). A total of 152 patients receiving MUA ≥12 weeks after primary TKA from 2014 to 2021 were reviewed. The primary outcome measured was change in range of motion (ROM). We tracked intraoperative complications and the need for repeat MUA or open procedure for continued stiffness after initial MUA. Three subgroups were analyzed: Group 1 included 58 knees between 12 weeks and 6 months after TKA, Group 2 included 44 knees between 6 and 12 months after TKA, and Group 3 included 50 knees ≥12 months after TKA. Analysis included descriptive statistics and univariate analysis, with α <0.05. Groups 1 to 3 all significantly increased their overall ROM by 20.9, 19.2, and 22.0 degrees, respectively. All groups significantly increased their flexion and extension from preoperatively. Group 1 had one intraoperative supracondylar femur fracture (1.7%) requiring open reduction and internal fixation, and five patients required repeat MUA or open procedure (8.6%). Group 2 had no intraoperative fractures, and five patients required repeat MUA or open procedure (11.4%). Group 3 had one intraoperative tibial tubercle avulsion fracture managed conservatively (2.0%) and one repeat MUA (2.0%). Late MUA resulted in significantly improved ROM in all groups. ROM improved more as the time from index TKA increased, although statistically insignificant. Repeat MUA or open procedure rate decreased with MUA ≥12 months from TKA, although statistically insignificant. The overall intraoperative fracture risk was 1.3%.

Seven human cadaveric specimens were tested on a knee simulator to study the effect of femoral component external rotation and patellar component medialization on the patellofemoral joint after total knee arthroplasty. The femoral component was externally rotated by 0°, 2.5°, and 5°, and the patellar component was positioned at the geometric center and 3.7mm medial to the geometric center. Only one of the specimens subluxed. Medialization of the patellar component was found to decrease the lateral force on the patella and increase the lateral tilt of the patella. The external rotation of the femoral component had a complicated interaction with the patella, and the overall effect was less obvious. Neither the femoral component rotation nor the patellar component medialization had a large effect on the normal patellofemoral forces.

Outpatient surgery can be performed in three different environments: (1) standard hospital operating room (OR), (2) hospital outpatient department (HOPD), and (3) free-standing ambulatory surgery centers (hereafter referred to as “ASC”). Although initially met with skepticism, a growing body of evidence suggests that TJA can be safely performed in an outpatient environment. The impetus for this shift is multifactorial. ASCs represent a lower cost alternative to hospitals for outpatient procedures. ASCs are designed to accommodate high volume efficiently and provide surgeons an environment to perform more cases in less time than a traditional hospital environment, with more personal control. There may be opportunities for surgeons to participate as equity partners in certain facilities, which provides additional revenue. Finally, patients enjoy the efficiency at ASCs and report high patient satisfaction. That being said, safely performing TJA in an ASC is not without its challenges. Understanding the fundamental differences inherent in performing an outpatient joint arthroplasty at an ASC as opposed to a hospital or HOPD is critical for success, patient safety, and quality. The purpose of this chapter is to highlight the limitations and obstacles of performing TJA at an ASC. We will address not just the challenges, but also propose solutions and provide insights that can assist in ensuring surgeons can transition to an ASC environment efficiently.KeywordsTotal hip arthroplastyTHATotal knee arthroplastyTKAUnicompartmental knee arthroplastyUKAOutpatientAmbulatoryAmbulatory surgery centerASCJoints

Background: Instability is a common mode of failure after primary total knee arthroplasty (TKA). Surgical management includes total revision and isolated polyethylene exchange. This study aimed to evaluate outcomes after isolated polyethylene exchange for instability in one of the largest cohorts reported to date. Methods: This is a retrospective study of 87 patients and 93 cases of isolated polyethylene exchange after TKA for instability at a tertiary academic center. Preoperative and postoperative Knee Society Scores were compared using paired T-testing with a significance level set at p = .05. Secondary outcomes included satisfaction, complications, rates of additional surgery, and recurrent instability. Results: Of the 87 patients, 61 patients had both pre and post-operative KSS-Knee scores and 60 with matched KSS-Functional scores. KSS-Knee scores significantly increased from 63.78 to 83.13 (p < .05), and KSS-Functional scores increased from 63.80 to 84.00 (p < .05). Seven of 93 cases (7.78%) cases required additional surgery at an average of 3.8 years, including two for recurrent instability. Nine (10%) cases were initially satisfied but developed recurrent instability at an average of 27.6 months. Conclusion: Isolated polyethylene exchange after TKA for instability resulted in significantly increased reported clinical outcome scores. Isolated polyethylene exchange after TKA for recurrent instability may be a viable option but surgeons should consider the rate of complications requiring surgery as well as high rate of recurrent instability. More studies with longer-term follow-up are required to further identify which patients may benefit the most from isolated polyethylene exchange after TKA for recurrent instability.

Introduction: Synovial fluid analysis is an essential tool in diagnosing periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). However, concern exists that aspiration may introduce infection into a non-infected joint. Therefore, the purpose of this study was to evaluate the incidence of iatrogenic PJI following diagnostic knee aspiration done within 6 months of the primary TKA. Methods: Between 2017 and 2021, the senior surgeon performed over 4,000 primary TKAs and aspirated 155 knees in 137 patients for whom there was a suspicion for PJI within six months of their primary TKA. There were twenty-two knees diagnosed as infected from the initial aspiration and therefore were excluded from the study. The remaining 133 aspirates in 115 patients who were negative for infection were followed for six months for signs and symptoms of PJI to elucidate whether aspiration introduced infection into an initially non-infected joint. Results: There were 70 of 133 knees (52.6%) aspirated between 0 to 6 weeks after index TKA, 40 of 133 (30.1%) between 6 weeks to 3 months, and 23 of 133 (17.3%) between 3 to 6 months. At final follow-up, none of the 133 initially non-infected knees exhibited evidence of subsequent iatrogenic PJI or had subsequent surgery for infection. Conclusion: While joint aspiration is a procedure with inherent risks, this study shows that the rate of iatrogenic PJI is extremely low (0%). Therefore, if infection is suspected, the surgeon should consider joint aspiration, even in the initial post-operative period, as the risk for introducing infection is far outweighed by the risk of missing an infection.

Purpose The use of implant arthroplasty in the distal radioulnar joint is increasing. Two main types of implants are commonly used, ulnar head prosthesis (UHP) and hemi or semi-constrained total distal radioulnar joint arthroplasty. The literature consists mainly of small patient series. The purpose of this study was to examine our long-term outcomes of distal radioulnar joint arthroplasty. Methods Patient data were collected in a patient registry from 2000 to 2019. The follow-up included radiographic examination, physical examination, Mayo Wrist Scores, pain level, range of motion, and grip strength. Reoperations were recorded. The implants were a semi-constrained prosthesis and a metallic UHP. The mean age at surgery was 50 years. Patient demographics were similar, but the semi-constrained group had a higher preoperative percentage of instability (85 vs 52 percent). The median follow-up time was 30 months for the semi-constrained implants group and 102 months for the UHP group. Results A total of 53 primary semi-constrained total joint arthroplasties and 102 UHPs were included. The grip strength and Mayo Wrist Score improved for both the implant groups. Pain reduced in 76% of the patients. Supination improved for the semi-constrained total joint arthroplasty group. Lifting capacity was better in the semi-constrained total joint arthroplasty patients. The unadjusted reoperation rate was 23% for the semi-constrained implants group and 34% for the UHP group. Twenty-two implants were bilateral; these had comparable results to unilateral implants. Kaplan–Meier survival curves demonstrated 94% survival rate for the semi-constrained implants group and 87% survival for the UHP group after 5 years. The risk factors associated with reoperation for the combined implant group included younger age at surgery, previous wrist surgery, ulnar shortening, and wrist fusion. Conclusions Distal radioulnar joint arthroplasty improved functional outcomes in both the implant groups, but reoperations were frequent. The semi-constrained implants group had better lifting capacity. The bilateral implants had comparable outcomes to the unilateral implants. Type of study/level of evidence Therapeutic IV.

Purpose To evaluate the functional outcome and complications following primary ulnar head or total distal radial ulnar joint (DRUJ) arthroplasty in patients who have a partial or total wrist fusion. Methods We conducted a retrospective review of 33 primary DRUJ implants in 31 patients who had a partial or total wrist fusion. Follow-up time averaged 67 months. There were 11 partial and 22 total wrist fusions with 22 ulnar head prosthesis and 11 total DRUJ implants. The mean age of the patients was 49 years. Eighty-one percent had previous surgeries with an average number of 4.6 previous wrist procedures. Pre- and postoperative pain levels were recorded. Mayo Wrist Scores were calculated. Grip strength, range of motion (ROM), and post-operative complications were noted. Results The pain scores improved in 67% of the patients. The Mayo Wrist Score improved significantly from a mean of 39 preoperatively to 51 postoperatively. The grip strength and pro-supination remained stable. The wrist ROM also remained stable in the patients with partial wrist fusions. During the follow-up period, 10 (30%) of the DRUJ implants were explanted, with a trend toward higher explantation rates in total wrist fusions with one in the partial fusion group and nine in the total wrist fusion group. Four of the explantations happened in the first postoperative year. Nineteen (61%) of the patients required a second surgery for a DRUJ implant-related complication; this rate was similar between the partial and total fusion groups. Conclusions DRUJ replacement resulted in improved pain scores and Mayo wrist scores in the majority of patients; however, the combination of primary DRUJ arthroplasty and total wrist fusion was associated with high complication rates. Surgeons should be aware of the high complication rate seen with DRUJ arthroplasty when combined with total wrist fusion.

Background Progressive arthritis in the unresurfaced compartments of the knee is one failure mode after partial knee arthroplasty(PKA). While progressive arthritis after PKA is typically treated with revision to TKA(rTKA), staged bicompartmental knee arthroplasty(sBiKA) –the addition of another PKA - is an alternative. This study compared outcomes of sBiKA and rTKA for progressive arthritis after PKA. Methods A retrospective comparative study of non-consecutive cases at four institutions was performed in patients with an intact PKA, without loosening or wear, who underwent sBiKA (n=27) or rTKA (n=30), for progressive osteoarthritis. Outcomes studied were new Knee Society Function and Objective Scores(KSSF, KSSO), KOOS, Jr., ROM, operative times, length of stay, complication rates and the need for reoperations. Results Mean time to conversion was 7.4±6 years for sBiKA and 9.7±8 for rTKA, p=0.178. Patient demographics and pre-operative outcomes were similar between cohorts. At an average of 5.7±3 (sBiKA) and 3.2±2 years (rTKA), KOOS, Jr. significantly improved, p<0.001, by an equivalent amount. Post-operative KSSO and KSSF were significantly higher in the sBiKA cohort, respectively, (90.4±10 vs 72.1±20, p<0.001) and (80.3±18 vs 67.1±19, p=0.011). sBiKA patients had significantly greater improvement in KSSO (30.7±33 vs. 5.2±18, p=0.003). 1 sBiKA patient underwent reoperation for continued pain. Conclusion SBiKA has equivalent survivorship, but greater improvement in functional outcomes as rTKA at short to midterm follow-up. Given the shorter operative times and length of stay, sBiKA is a safe and cost effective alternative to rTKA for progressive osteoarthritis following PKA. Nevertheless further follow-up is necessary to determine whether sBiKA is a durable option.