Total joint arthroplasty following solid organ transplants: complications and mid-term outcomes.

PURPOSE: Survival after solid organ transplant (SOT) is improving, and demand for total joint arthroplasty (TJA) among SOT recipients is rising. Outcomes including revision, periprosthetic joint infection, and survivorship based on SOT type are variable. We sought to compare peri-operative complications, implant survivorship, and mortality for patients undergoing TJA following SOT. METHODS: A retrospective review of the institutional database for primary TJA among SOT recipients from 2000 to 2020 was performed. Revisions, conversion TJA, and patients with multiple organ transplants were excluded. Patients were stratified by transplant organ. Transfusions, 90-day readmissions and emergency department (ED) visits, revisions, and mortality were compared using descriptive statistics and Cox proportional hazard ratios. RESULTS: A total of 119 total hip arthroplasties (THA) and 63 total knee arthroplasties (TKA) in SOT recipients were studied. Most common SOT was renal (39%), then lung (27%), liver (24%), and heart (10%). TKA postoperative transfusion rates varied by organ (p = 0.037; [heart 0%, liver 9.5%, renal 24.0%, lung 50.0%]). Implant survivorship was 95.6% at one year (95% CI 90.3-98.1) and 92.1% at four years (83.9-96.3). Mortality was 2.9% at one year (95% CI 1.1-7.4) and 23.2% at four years (95% CI 16.1-32.3). After adjusting for procedure, duration from transplant to TJA, age, and Elixhauser Index, lung recipients had higher mortality versus heart (RR 4.39 [95% CI 1.64-15.38]; p = 0.002), kidney (7.98 [3.04-24.61]; p < 0.001), and liver (7.98 [3.04-24.61; p < 0.001) patients. CONCLUSION: TJA after SOT yields acceptable peri-operative outcomes and implant survivorship, but mortality risk is substantial, especially among lung transplant recipients.

Do Corticosteroids Attenuate the Peri-Operative Acute Phase Response After Total Knee Arthroplasty?

BACKGROUND: Following tissue injury, the acute phase response (APR) functions to survive and then repair injured tissue. An exuberant APR, which can be evoked by total knee arthroplasty (TKA), results in a hyper-inflammatory state, leading to pain, nausea, venous thromboembolism, or potentially life-threatening complications. Here, we observed the effects of peri-operative dexamethasone on the APR following TKA by trending C-reactive protein (CRP, mg/L) and fibrinogen (mg/dL). We hypothesize that the anti-inflammatory effects of dexamethasone can attenuate the APR after TKA and will be associated with decreased post-operative pain and nausea. METHODS: A retrospective case-control study was performed on 188 unilateral TKA procedures. The patients were divided into a group receiving dexamethasone (10 mg intra-operatively and on post-operative day [POD] 1) and a group receiving no corticosteroids. Post-operative CRP, fibrinogen, morphine equivalents, and anti-emetic doses were recorded. RESULTS: Compared to the non-steroid group, patients receiving dexamethasone yielded a significantly decreased CRP on POD0 (5.5 vs 8.3), POD1 (11.8 vs 22.0), and POD2 (85.5 vs 148.9). A significant decrease in fibrinogen in patients receiving dexamethasone was seen on POD2 (460.0 vs 530.2). There was an increase in fibrinogen within the dexamethasone cohort at the 2-week visit (535.4 vs 488.9). Post-operative morphine equivalents administered were significantly decreased in patients receiving dexamethasone, but no difference in anti-emetic use was appreciated. CONCLUSION: These data support the hypothesis that the APR following TKA can be attenuated pharmacologically by corticosteroids. Further studies are needed to determine whether the attenuation of the APR with the use of corticosteroids prevents complications following TKA.

Biomechanical Strength of Scaphoid Partial Unions.

Background It remains unknown how much force a partially united scaphoid can sustain without refracturing. This is critical in determining when to discontinue immobilization in active individuals. Purpose The purpose of this study was to test the biomechanical strength of simulated partially united scaphoids. We hypothesized that no difference would exist in load-to-failure or failure mechanism in scaphoids with 50% or more bone at the waist versus intact scaphoids. Materials and Methods Forty-one cadaver scaphoids were divided into four groups, three experimental osteotomy groups (25, 50, and 75% of the scaphoid waist) and one control group. Each was subjected to a physiologic cantilever force of 80 to 120 N for 4,000 cycles, followed by load to failure. Permanent deformation during physiologic testing and stiffness, max force, work-to-failure, and failure mechanism during load to failure were recorded. Results All scaphoids survived subfailure conditioning with no significant difference in permanent deformation. Intact scaphoids endured an average maximum load to failure of 334 versus 321, 297, and 342 N for 25, 50, and 75% groups, respectively, with no significant variance. There were no significant differences in stiffness or work to failure between intact, 25, 50, and 75% groups. One specimen from each osteotomy group failed by fracturing through the osteotomy; all others failed near the distal pole loading site. Conclusion All groups behaved similarly under physiologic and load-to-failure testing, suggesting that inherent stability is maintained with at least 25% of the scaphoid waist intact. Clinical Relevance The data provide valuable information regarding partial scaphoid union and supports mobilization once 25% union is achieved.

Commonalities, differences, and challenges with patient-derived outcome measurement tools: function/activity scales.

BACKGROUND: There is a critical need to evaluate the success of orthopaedic treatments through valid outcome measures. Previous attempts to express patient outcomes using a single aggregate score led to scores that were ambiguous, often insensitive to change, and poorly correlated with the patient's assessment of the outcome of surgical procedures. WHERE ARE WE NOW?: Numerous patient-reported outcome measurement tools have been developed for assessment of patients' level of activity and functional status, especially after joint arthroplasty. However, most tools assume an idealized set of prescribed activities independent of the age, activity level, and lifestyle of each individual. Few instruments are designed to capture the priorities of individual patients, especially those involved in high-demand sporting and recreational activities. WHERE DO WE NEED TO GO?: We need valid outcome measures that provide a meaningful, individualized assessment of the functional status of each patient, taking into account the lifestyle and expectation of each individual. This advance in outcome measurement will allow clinicians to individualize treatment and provide patients with an accurate estimate of the outcome of alternative treatments and procedures. HOW DO WE GET THERE?: Much more comprehensive information is needed to characterize the activities, abilities, and physical aspirations of individual patients. This could form a database for the development of predictive models relating individual characteristics to functional outcomes. Statistical tools are needed to minimize the burden on patients in completing questionnaires to access predictive data and to ensure that all outcome assessments are psychometrically valid.

The effect on external rotation of an anchor placed anterior to the biceps in type 2 SLAP repairs in a cadaveric throwing model.

PURPOSE: This study examined whether there is a difference in external rotation (ER) between type 2 SLAP repairs consisting of anchors placed only posterior to the biceps insertion compared with repairs with an additional anchor placed anterior to the biceps. METHODS: Seven cadaveric shoulders from donors with a mean age of 39.4 years were tested. Type 2 SLAP lesions were created, followed by a 3-anchor repair: a standard repair with 2 anchors posterior to the biceps plus an additional anchor anterior to the biceps. The specimens were placed on a material testing system machine and rotation was measured under a constant torque. The sutures were then removed sequentially from anterior to posterior during testing. RESULTS: The average ER of the intact shoulder was 115.7° ± 2.6°. After SLAP tear creation and cyclic loading, the ER was 118.5° ± 2.6°, which decreased to 116.5° ± 2.6° after repair. This corresponds to a reduction of 2.0° of ER (P < .0001) with the repair. After release of the anterior anchor, the ER increased to 117.9° ± 2.6°, which corresponds to an increase in shoulder motion of 1.4° of ER (P = .0011). Additional release of the middle anchor, leaving only the posterior anchor intact, resulted in 118.0° ± 2.7° of ER, which corresponds to an increase of only 0.1° of ER (P = .7667). CONCLUSIONS: Following type 2 SLAP repair in the cadaveric shoulder, removing the effect of the anchor anterior to the biceps resulted in a small but statistically significant increase in ER. The anterior anchor had the greatest effect on ER. The presence of 1 or 2 anchors posterior to the biceps did not have a significant effect on rotation. CLINICAL RELEVANCE: When performing SLAP repairs on those in whom even a small loss of ER would be detrimental, such as baseball pitchers, avoidance of the use of an anchor anterior to the biceps should be considered.

The financial impact of joint registries in identifying poorly performing implants.

We analyzed the effect of the Australian National Joint Registry on the cost of joint arthroplasty through identification of implants with higher than expected failure rates. From 2003 to 2007, 242,454 primary joint arthroplasties were performed in Australia at a total cost of $4.1 billion. Of these cases, 19,224 were performed using components identified by the Registry as poorly performing. If all of these cases were performed using average-performing designs, the number of revisions would have dropped by 28.6%. We also predicted that over a 5-year period after Registry identification, 32,807 primary procedures would be performed using poorly performing implants. If implants of average longevity were selected instead, we predict that 25.8% fewer revision procedures would be needed, ranging from 7% in unicompartmental knee replacement to 47% in total hip arthroplasty. This change in practice is expected to save 10.2% of direct costs, corresponding to $14 million over a 5-year period.

Development of a new Knee Society scoring system.

BACKGROUND: The Knee Society Clinical Rating System was developed in 1989 and has been widely adopted. However, with the increased demand for TKA, there is a need for a new, validated scoring system to better characterize the expectations, satisfaction, and physical activities of the younger, more diverse population of TKA patients. QUESTIONS/PURPOSES: We developed and validated a new Knee Society Scoring System. METHODS: We developed the new knee scoring system in two stages. Initially, a comprehensive survey of activities was developed and administered to 101 unilateral TKA patients (53 women, 48 men). A prototype knee scoring instrument was developed from the responses to the survey and administered to 497 patients (204 men, 293 women; 243 postoperatively, 254 preoperatively) at 15 medical institutions within the United States and Canada. Objective and subjective data were analyzed using standard statistical and psychometric procedures and compared to the Knee Injury and Osteoarthritis Score and SF-12 scores for validation. Based on this analysis, minor modifications led to the new Knee Society Scoring System. RESULTS: We found the new Knee Society Scoring System to be broadly applicable and to accurately characterize patient outcomes after TKA. Statistical analysis confirmed the internal consistency, construct and convergent validity, and reliability of the separate subscale measures. CONCLUSIONS: The new Knee Society Scoring System is a validated instrument based on surgeon- and patient-generated data, adapted to the diverse lifestyles and activities of contemporary patients with TKA. This assessment tool allows surgeons to appreciate differences in the priorities of individual patients and the interplay among function, expectation, symptoms, and satisfaction after TKA.

Influence of gender on age of treatment with TKA and functional outcome.

BACKGROUND: Previous studies suggest differences may exist between men and women in terms of knee function before and after total knee replacement. This may be related to the efficacy of the procedure itself or to differences in the severity of disability of male and female patients at the time of surgery. QUESTIONS/PURPOSES: We evaluated differences in the age, preoperative deformity, range-of-motion, and Knee Society scores of men and women who underwent TKA. All parameters were measured at the time of the initial preoperative evaluation and at postoperative followup. METHODS: We studied 698 patients who underwent elective TKA between 1996 and 2007. This population consisted of 428 women (61%) and 270 men (39%), all of whom underwent rehabilitation utilizing a standardized hyperflexion protocol with immediate initiation of full weight-bearing postoperatively. RESULTS: The men were on average three years younger than the women (mean 63.5 versus 66.6 years, respectively). Preoperative ROM, postoperative ROM, and changes in ROM and body mass index were similar between groups. Knee Society Knee scores were similar preoperatively (47.4 [men] versus 46.7 [women]), but four points higher in men at followup (89.2 versus 85.2). Women had lower Knee Function scores than men preoperatively (45.2 versus 57.1), and postoperatively (65.3 versus 73.9). CONCLUSIONS: Women who undergo TKA seek treatment at a later stage than men and have greater functional disability at the time of surgery. Differences in functional scores persist after TKA. Earlier initiation of treatment may enhance postoperative outcome. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.