Severity of Chronic Venous Insufficiency on Primary Total Knee Arthroplasty Outcomes.

BACKGROUND: More than 700,000 people in the United States undergo total knee arthroplasty (TKA) each year. Chronic venous insufficiency (CVI) affects 5% to 30% of adults, sometimes resulting in leg ulceration. These CVI cases in TKAs have been associated with worse outcomes; however, we found no study differentiating CVI severity. METHODS: This retrospective study analyzed TKA outcomes at one institution from 2011 to 2021 using patient-specific codes. Analyses included short-term complications (< 90 days postoperative), long-term complications (< 2 years), and CVI status (yes/no; simple/complex/unclassified). Complex CVI consisted of pain, ulceration, inflammation, and/or other complications. Revisions within 2 years and readmissions within 90 days post-TKA were assessed. Composite complications included short-term and long-term complications, revisions, and readmissions. Multivariable logistic regressions predicted complication (any/long/short) as a function of CVI status (yes/no; simple/complex) and potential confounding variables. Of 7,665 patients, 741 (9.7%) had CVI. Among CVI patients, 247 (33.3%) had simple CVI, 233 (31.4%) had complex CVI, and 261 (35.2%) had unclassified CVI. RESULTS: There was no difference in CVI versus control in composite complications (P = .722), short-term complications (P = .786), long-term complications (P = .15), revisions (P = .964), or readmissions (P = .438) postadjustment. Composite complication rates were 14.0% without CVI, 16.7% with complex CVI, and 9.3% with simple CVI. Complication rates differed between simple and complex CVI (P = .035). CONCLUSION: Overall, CVI did not affect postoperative complications versus control. Patients who have complex CVI are at higher risk for post-TKA complications compared to those who have simple CVI.

Disparities in Elective and Nonelective Total Hip Arthroplasty.

BACKGROUND: Prior studies have shown disparities in utilization of primary and revision total hip arthroplasty (THA). However, little is known about patient population differences associated with elective and nonelective surgery. Therefore, the aim of this study was to explore factors that influence primary utilization and revision risk of THA based on surgery indication. METHODS: Data were obtained from 7,543 patients who had a primary THA from 2014 to 2020 in a database, which consists of multiple health partner systems in Louisiana and Texas. Of these patients, 602 patients (8%) underwent nonelective THA. THA was classified as "elective" or "nonelective" if the patient had a diagnosis of hip osteoarthritis or femoral neck fracture, respectively. RESULTS: After multivariable logistic regression, nonelective THA was associated with alcohol dependence, lower body mass index (BMI), women, and increased age and number of comorbid conditions. No racial or ethnic differences were observed for the utilization of primary THA. Of the 262 patients who underwent revision surgery, patients who underwent THA for nonelective etiologies had an increased odds of revision within 3 years of primary THA (odds ratio (OR) = 1.66, 95% Confidence Interval (CI) = 1.06-2.58, P-value = .025). After multivariable logistic regression, patients who had tobacco usage (adjusted odds ratio (aOR) = 1.36, 95% CI = 1.04-1.78, P-value = .024), alcohol dependence (aOR = 2.46, 95% CI = 1.45-4.15, P-value = .001), and public insurance (OR = 2.08, 95% CI = 1.18-3.70, P-value = .026) had an increased risk of reoperation. CONCLUSION: Demographic and social factors impact the utilization of elective and nonelective primary THA and subsequent revision surgery. Orthopaedic surgeons should focus on preoperative counseling for tobacco and alcohol cessation as these are modifiable risk factors to directly decrease reoperation risk.

Improved Treatment Effect of Triamcinolone Acetonide Extended-Release in Patients with Concordant Baseline Pain Scores on the Average Daily Pain and Western Ontario and McMaster Universities Osteoarthritis Index Pain Scales.

INTRODUCTION: A phase 3 randomized controlled study comparing triamcinolone acetonide extended-release (TA-ER) to conventional TA crystalline suspension (TAcs) reported variable efficacy results. Enrollment criteria may have contributed to this discrepancy, as moderate-to-severe average daily pain (ADP) was required at baseline, whereas no limitations were placed on Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC-A) pain severity. We conducted a post hoc sensitivity analysis to compare treatment effects in patients reporting moderate-to-severe osteoarthritis (OA) pain on both scales. METHODS: Participants > 40 years old with symptomatic knee OA were randomly assigned to a single intra-articular injection of TA-ER 32 mg, TAcs 40 mg, or saline-placebo and followed for 24 weeks. Patient-reported ADP, WOMAC-A, rescue medication usage, and adverse events (AEs) were assessed. Participants who reported moderate-to-severe OA pain at baseline using both instruments (ADP ≥ 5 to ≤ 9, maximum 10 and WOMAC-A ≥ 2, maximum 4) were categorized as "concordant" pain reporters; patients with baseline moderate-to-severe OA on ADP only were termed "discordant" pain reporters. RESULTS: Two-hundred-ninety-two concordant pain reporters of 484 total subjects received TA-ER 32 mg (n = 95), TAcs 40 mg (n = 100), or saline-placebo (n = 97). Baseline characteristics and AE profiles of the concordant and discordant pain responders were consistent with the full analysis population. Among concordant pain reporters, TA-ER significantly (p < 0.05) improved ADP scores vs. TAcs (weeks 5-19; area-under-the-effect [AUE]weeks1-12; AUEweeks1-24) and saline-placebo (weeks 1-20; AUEweeks1-12; AUEweeks1-24). At week 12, a higher proportion reported no knee pain (ADP = 0) with TA-ER (~ 28%) vs. TAcs (~ 8%). TA-ER significantly improved WOMAC-A vs. TAcs at weeks 4, 8, and 12, with significant reduction in rescue medication usage observed with TA-ER from weeks 2 to 20 vs. TAcs. CONCLUSIONS: In patients reporting moderate-to-severe knee OA pain at baseline based on concordant ADP and WOMAC-A scores, TA-ER provided statistically significant pain relief for ≥ 12 weeks compared with conventional TAcs. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02357459.

Osteoarthritis is a chronic condition that greatly impacts patients. Pain is the most common symptom of osteoarthritis. Clinical trials evaluating the effects of new drugs to treat osteoarthritis pain frequently use scales to rate overall pain following treatment. Patients may rate their pain using a number that best describes their pain, with the lowest number typically meaning "no pain," and the highest number typically meaning "pain as bad as you can imagine." Other rating scales may be used to rate pain in situations commonly associated with osteoarthritis.Results from a large clinical trial demonstrated that injection of an extended-release steroid significantly reduced pain compared with a conventional steroid injection on only one of the two pain-reporting scales used in the trial. A closer look found that some patients reported their pain differently on the two rating scales at the start of the trial, with some reporting moderate-to-severe pain using one questionnaire and mild pain using the other. Here, we focused on those patients who reported having moderate-to-severe osteoarthritis knee pain on both pain scales at the start and found that the pain relief benefit associated with the extended-release steroid injection was greatly improved compared with the conventional steroid injection with both measures. Patients receiving the extended-release steroid injection also decreased their use of rescue medication for pain relief.

Metrics of OsteoChondral Allografts (MOCA) Group Consensus Statements on the Use of Viable Osteochondral Allograft.

BACKGROUND: Osteochondral allograft (OCA) transplantation has evolved into a first-line treatment for large chondral and osteochondral defects, aided by advancements in storage protocols and a growing body of clinical evidence supporting successful clinical outcomes and long-term survivorship. Despite the body of literature supporting OCAs, there still remains controversy and debate in the surgical application of OCA, especially where high-level evidence is lacking. PURPOSE: To develop consensus among an expert group with extensive clinical and scientific experience in OCA, addressing controversies in the treatment of chondral and osteochondral defects with OCA transplantation. STUDY DESIGN: Consensus statement. METHODS: A focus group of clinical experts on OCA cartilage restoration participated in a 3-round modified Delphi process to generate a list of statements and establish consensus. Questions and statements were initially developed on specific topics that lack scientific evidence and lead to debate and controversy in the clinical community. In-person discussion occurred where statements were not agreed on after 2 rounds of voting. After final voting, the percentage of agreement and level of consensus were characterized. A systematic literature review was performed, and the level of evidence and grade were established for each statement. RESULTS: Seventeen statements spanning surgical technique, graft matching, indications, and rehabilitation reached consensus after the final round of voting. Of the 17 statements that reached consensus, 11 received unanimous (100%) agreement, and 6 received strong (80%-99%) agreement. CONCLUSION: The outcomes of this study led to the establishment of consensus statements that provide guidance on surgical and perioperative management of OCAs. The findings also provided insights on topics requiring more research or high-quality studies to further establish consensus and provide stronger evidence.

An Expert Consensus Statement on the Management of Large Chondral and Osteochondral Defects in the Patellofemoral Joint.

BACKGROUND: Cartilage lesions of the patellofemoral joint constitute a frequent abnormality. Patellofemoral conditions are challenging to treat because of complex biomechanics and morphology. PURPOSE: To develop a consensus statement on the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint using a modified Delphi technique. STUDY DESIGN: Consensus statement. METHODS: A working group of 4 persons generated a list of statements related to the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint to form the basis of an initial survey for rating by a group of experts. The Metrics of Osteochondral Allografts (MOCA) expert group (composed of 28 high-volume cartilage experts) was surveyed on 3 occasions to establish a consensus on the statements. In addition to assessing agreement for each included statement, experts were invited to propose additional statements for inclusion or to suggest modifications of existing statements with each round. Predefined criteria were used to refine statement lists after each survey round. Statements reaching a consensus in round 3 were included within the final consensus document. RESULTS: A total of 28 experts (100% response rate) completed 3 rounds of surveys. After 3 rounds, 36 statements achieved a consensus, with over 75% agreement and less than 20% disagreement. A consensus was reached in 100.00% of the statements relating to functional anatomy of the patellofemoral joint, 88.24% relating to surgical indications, 100.00% relating to surgical technical aspects, and 100.00% relating to rehabilitation, with an overall consensus of 95.5%. CONCLUSION: This study established a strong expert consensus document relating to the functional anatomy, surgical indications, donor graft considerations for osteochondral allografts, surgical technical aspects, and rehabilitation concepts for the management of large chondral and osteochondral defects in the patellofemoral joint. Further research is required to clinically validate the established consensus statements and better understand the precise indications for surgery as well as which techniques and graft processing/preparation methods should be used based on patient- and lesion-specific factors.

Safety and Efficacy of Repeat Administration of Triamcinolone Acetonide Extended-release in Osteoarthritis of the Knee: A Phase 3b, Open-label Study.

INTRODUCTION: The aim of this work is to assess the safety and efficacy of repeat administration of triamcinolone acetonide extended-release (TA-ER) in patients with symptomatic knee osteoarthritis (OA), including those with advanced radiographic severity. METHODS: In this phase 3b, single-arm, open-label study, patients aged ≥ 40 years received the first intra-articular TA-ER injection on day 1. Patients received the second injection timed to the response to the first injection (at either week 12, 16, 20, or 24). Patients who received two injections were evaluated every 4 weeks for 52 weeks. Safety was evaluated via treatment-emergent adverse events and any change at 52 weeks in index-knee radiographs (chondrolysis, osteonecrosis, insufficiency fractures, subchondral bone changes). Exploratory efficacy endpoints included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-A (pain), -B (stiffness), -C (function), and Knee Injury and Osteoarthritis Outcome Score-Quality of Life (KOOS-QoL) after each injection. Initiative in Methods, Measurements and Pain Assessment in Clinical Trials (IMMPACT) criteria were used to determine moderate and substantial treatment response. RESULTS: A total of 208 patients were enrolled and received the first injection of TA-ER; 179 (86.1%) received the second injection (median time to second injection: 16.6 weeks). Both injections were well tolerated, with no unexpected adverse events or significant radiographic changes at week 52. The magnitude and duration of clinical benefit after the first and second injections were similar, and most patients reported a substantial (≥ 50%) analgesic response after both doses. CONCLUSIONS: Repeat administration of TA-ER using a flexible dosing schedule timed to patient response was well tolerated, with no radiographic evidence of cartilage impact. Both injections resulted in similar improvements in OA symptoms across a broad spectrum of disease severity reflective of that seen in clinical practice. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov identifier: NCT03046446. FUNDING: Flexion Therapeutics, Inc. Plain language summary available for this article.

Effects of a Single Intra-Articular Injection of a Microsphere Formulation of Triamcinolone Acetonide on Knee Osteoarthritis Pain: A Double-Blinded, Randomized, Placebo-Controlled, Multinational Study.

BACKGROUND: Intra-articular corticosteroids relieve osteoarthritis pain, but rapid systemic absorption limits efficacy. FX006, a novel, microsphere-based, extended-release triamcinolone acetonide (TA) formulation, prolongs TA joint residence and reduces systemic exposure compared with standard TA crystalline suspension (TAcs). We assessed symptomatic benefits and safety of FX006 compared with saline-solution placebo and TAcs. METHODS: In this Phase-3, multicenter, double-blinded, 24-week study, adults ≥40 years of age with knee osteoarthritis (Kellgren-Lawrence grade 2 or 3) and average-daily-pain (ADP)-intensity scores of ≥5 and ≤9 (0 to 10 numeric rating scale) were centrally randomized (1:1:1) to a single intra-articular injection of FX006 (32 mg), saline-solution placebo, or TAcs (40 mg). The primary end point was change from baseline to week 12 in weekly mean ADP-intensity scores for FX006 compared with saline-solution placebo. Secondary end points were area-under-effect (AUE) curves of the change in weekly mean ADP-intensity scores from baseline to week 12 for FX006 compared with saline-solution placebo, AUE curves of the change in weekly mean ADP-intensity scores from baseline to week 12 for FX006 compared with TAcs, change in weekly mean ADP-intensity scores from baseline to week 12 for FX006 compared with TAcs, and AUE curves of the change in weekly mean ADP-intensity scores from baseline to week 24 for FX006 compared with saline-solution placebo. Exploratory end points included week-12 changes in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee Injury and Osteoarthritis Outcome Score Quality of Life (KOOS-QOL) subscale scores for FX006 compared with saline-solution placebo and TAcs. Adverse events were elicited at each inpatient visit. RESULTS: The primary end point was met. Among 484 treated patients (n = 161 for FX006, n = 162 for saline-solution placebo, and n = 161 for TAcs), FX006 provided significant week-12 improvement in ADP intensity compared with that observed for saline-solution placebo (least-squares mean change from baseline: -3.12 versus -2.14; p < 0.0001) indicating ∼50% improvement. FX006 afforded improvements over saline-solution placebo for all secondary and exploratory end points (p < 0.05). Improvements in osteoarthritis pain were not significant for FX006 compared with TAcs using the ADP-based secondary measures. Exploratory analyses of WOMAC-A, B, and C and KOOS-QOL subscales favored FX006 (p ≤ 0.05). Adverse events were generally mild, occurring at similar frequencies across treatments. CONCLUSIONS: FX006 provided significant, clinically meaningful pain reduction compared with saline-solution placebo at week 12 (primary end point). LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Factors Affecting the Union of Opening Wedge High Tibial Osteotomy Using a Titanium Wedge Plate.

BACKGROUND: Factors that can affect the success rate of high tibial osteotomy (HTO) include patient selection, surgical technique, type of fixation hardware, supplemental fixation, choice of bone graft, and rehabilitation protocol. The purpose of this study was to define the role of cortical hinge fractures in the risk of nonunion and collapse of opening wedge high tibial osteotomy. METHODS: A total of 60 patients (mean age, 40 years) who underwent 64 primary HTO procedures were identified from our operational database and observed at a mean follow-up of 2 years. Surgical correction was followed by immediate range of motion and a progressive weight-bearing protocol. Clinical and radiographic data were reviewed for patient demographics, bony union, cortical hinge fractures, loss of correction, and other complications. RESULTS: The average time to radiographic union was 14.8 weeks (range, 8-24). Loss of correction and/or collapse occurred in 6 cases (9.4%). Nine unrecognized cortical hinge fractures were retrospectively identified, of which 4 resulted in nonunion and collapse. We found a significantly higher incidence of unrecognized cortical hinge fractures in cases that collapsed (4/6, 66.7%) compared to cases that healed uneventfully (5/58, 8.6%) (P=0.003). CONCLUSION: A high index of suspicion must be maintained intraoperatively and postoperatively to identify and treat unstable constructs that increase the risk of nonunion and collapse after opening wedge HTO. This study's patient series explores the relationship between cortical hinge fracture and patient outcomes in the clinical setting by demonstrating a significantly higher rate of collapse and nonunion with unstable constructs.

Osteochondral Allograft Transplantation for Femoral Trochlear Dysplasia.

BACKGROUND: The risk factors for patellofemoral joint instability include laxity of medial patellar restraints, abnormal limb geometry, femoral and tibial malrotation, patella alta, and trochlear dysplasia. Femoral trochlear dysplasia is characterized by a hypoplastic or shallow trochlear groove. CASE REPORT: We report the case of a 31-year-old female with trochlear dysplasia and recurrent patella dislocations, laxity of the medial patellofemoral ligament (MPFL), and high-grade chondromalacia of the trochlea and the patella. Surgical treatment goals were to re-create a trochlear groove, restore bony restraint, and realign and offload the patella. First, a triplane tibial tubercle osteotomy (TTO) was performed, and the patella was everted 360° with a subvastus approach. The MPFL was reconstructed using a gracilis allograft. A fresh osteochondral allograft transplant trochlea was sized, and a 35-mm diameter graft was transplanted to re-create the groove. The TTO was secured in a new anterior, medial, and distal position. The patient was braced for 6 weeks and completed a rehabilitation protocol. At 9-month follow-up, she had made significant gains in range of motion (0°-140°) and activity compared to her preoperative status. She reported no pain or recurrent dislocations. CONCLUSION: This case demonstrates a viable surgical option for treatment of instability resulting from trochlear dysplasia with patellofemoral chondromalacia. The osteochondral allograft transplantation surgery technique allows patients to have a stable, pain-free knee joint and participate in activities compared to nonoperative management. However, the long-term outcomes of this procedure are unknown.

Biological and functional evaluation of a novel pyrolytic carbon implant for the treatment of focal osteochondral defects in the medial femoral condyle: assessment in a canine model.

BACKGROUND: Osteochondral defects continue to be a clinical treatment challenge, and when left untreated, may cause pain and functional impairment. Pyrolytic carbon is a unique isotropic biomaterial used in heart valve and small joint replacements due to its excellent wear properties and biocompatibility with bone and articular cartilage. Therefore, a proposed solution is to utilize a focal pyrolytic carbon hemiarthroplasty implant as an alternative resurfacing treatment strategy for isolated cartilage lesions. METHODS: A canine model (n = 9) was used to evaluate the in vivo histologic response and function of a pyrolytic carbon implant replacing a full-thickness osteochondral defect in the medial femoral condyle (MFC) of the knee. The gross appearance and histologic results were compared to an identical cobalt-chromium (Co-Cr) alloy implant placed in a defect in the contralateral MFC and evaluated up to 52 weeks. RESULTS: Extensive bone incorporation to the stem portion was observed for both implant types. The total mean histologic score for the cartilage of the MFC surrounding the pyrolytic carbon implants was significantly improved compared to that of the Co-Cr alloy implants at all evaluation periods (p < 0.05). Histologic grading and gross observations at 52 weeks for pyrolytic carbon implants were similar to those of Co-Cr alloy implants at 24 weeks. At 24 weeks, the mean total histologic score for Co-Cr alloy implants was 11.6 ± 0.7 (0-16 range point; 16 = normal appearance), while at 52 weeks, the mean total score for the pyrolytic carbon implants was 11.7 ± 1.3. Mean total histologic score of opposing medial tibia cartilage for the pyrolytic carbon implants was superior to that of the Co-Cr alloy group at all evaluation periods and significantly improved over the Co-Cr alloy implant group at 24 weeks (p = 0.001) and 52 weeks (p < 0.001). CONCLUSIONS: Use of a pyrolytic carbon implant for reconstruction of a focal cartilage defect demonstrated effective implant fixation and superior in vivo response compared to an identical Co-Cr alloy implant.

Relationships between ball velocity and throwing mechanics in collegiate baseball pitchers.

Although ball speed is considered a measure of success in baseball pitching, little is known about the relationship between ball velocity and pitching mechanics. Investigation of this relationship has been limited, and the studies carried out have varied in methodology. Three-dimensional, high-speed (240 Hz) video data were collected on fastballs from 54 collegiate baseball pitchers. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder and elbow were calculated. Multiple linear regression analysis was used to relate ball velocity and pitching mechanics. Ball velocity averaged 35 m/sec (79 mph) for the 54 college pitchers. Nearly 70% of the variability in ball speed can be explained by a combination of 10 parameters related to pitching mechanics. Body mass and 9 temporal and kinematic parameters related to pitching mechanics combine to account for 68% of the variance in ball velocity for a collegiate population of athletes. These variables can be manipulated via mechanical changes and sport-specific training to affect ball velocity. The results of the study can be used to increase ball velocity while at the same time minimizing stresses on the throwing arm elbow and shoulder. Improved training programs can begin to be developed based on these data.

The effect of low-intensity pulsed ultrasound on autologous osteochondral plugs in a canine model.

BACKGROUND: Low-intensity pulsed ultrasound promotes the enchondral portion of fracture healing, which has a direct stimulatory effect on cartilage formation and maturation. HYPOTHESIS: Daily ultrasound treatment positively affects the repair and incorporation of modified autologous osteochondral plugs in a canine model. STUDY DESIGN: Controlled laboratory study. METHODS: In 18 dogs, 2 autologous plugs separated from host cartilage by a 1.5-mm gap were created on the medial femoral condyle in both knees of each dog. One knee was treated daily with a clinically available ultrasound bone stimulator. Animals were sacrificed after 6 and 12 weeks of therapy and the articular surfaces evaluated grossly and histologically. RESULTS: Ultrasound-treated sites had significantly improved gross appearance at 6 weeks and histologic appearance at 6 and 12 weeks. The interface repair tissue of ultrasound-treated sites had a more normal translucent appearance than control sites. Ultrasound treatment improved the cell morphologic characteristics of the interface repair tissue and increased subchondral bone regeneration. Bonding of the interface repair tissue between plug and adjacent cartilage was significantly improved compared with control sites. CONCLUSION: Low-intensity pulsed ultrasound improved interface cartilage repair of autologous osteochondral plugs compared with controls in a canine model. CLINICAL RELEVANCE: Improvements in the quality and rate of repair of autologous osteochondral plugs may reduce postoperative recovery time and improve functional outcome.

Semiconstrained primary and revision total elbow arthroplasty with use of the Coonrad-Morrey prosthesis.

BACKGROUND: Semiconstrained total elbow prostheses are used routinely by many surgeons to treat a variety of severe elbow disorders. Our objective was to review the results of primary and revision total elbow arthroplasty with use of the Coonrad-Morrey prosthesis. The selected use of this semiconstrained implant in patients with instability and poor bone stock was hypothesized to provide inferior results compared with those in the published reports. METHODS: The results of sixty-seven semiconstrained total elbow arthroplasties that were performed in fifty-six patients between 1990 and 2003 were evaluated. Thirty-seven elbows had a primary arthroplasty and were followed for a mean of eighty-six months, and thirty elbows had a revision arthroplasty and were followed for a mean of sixty-eight months. Mayo elbow performance scores and radiographic analyses were used to assess the clinical results. RESULTS: In the primary arthroplasty group, the average flexion improved from 116 degrees to 135 degrees; average extension, from -40 degrees to -33 degrees; average pronation, from 60 degrees to 81 degrees; and average supination, from 60 degrees to 69 degrees. The improvements in flexion and pronation were significant (p<0.001 for both). Preoperatively, twenty-five (74%) of thirty-four elbows with data available had moderate or severe pain, whereas only four (11%) had pain postoperatively. The average postoperative Mayo score (and standard deviation) was 84+/-16. Eleven of the thirty-seven primary replacements failed, and the five-year survival rate was 72%. In the revision arthroplasty group, average flexion improved from 124 degrees to 131 degrees; average extension, from -32 degrees to -22 degrees; average pronation, from 66 degrees to 75 degrees; and average supination, from 64 degrees to 76 degrees; the improvement in supination was significant (p<0.05). Preoperatively, eighteen (64%) of the twenty-eight elbows with data available had moderate or severe pain, while only five (17%) had pain postoperatively. The average postoperative Mayo score was 85+/-16. Eleven of the thirty revision replacements failed, and the five-year survival rate was 64%. CONCLUSIONS: A Coonrad-Morrey semiconstrained total elbow arthroplasty provides excellent pain relief and good functional return in patients with severe destructive arthropathy. The higher prevalence of failure in this cohort compared with series reported elsewhere is likely due to adverse patient selection as this implant was reserved for more complex arthroplasties with severe bone loss and ligamentous laxity.

Autologous chondrocyte implantation.

Injuries to joint surfaces can result from acute high-impact or repetitive shear and torsional loads to the superficial zone of the articular cartilage architecture. The use of autologous chondrocyte implantation is promising and is associated with several potential long-term benefits. Proper patient selection and education are important factors for success.

Relationships between throwing mechanics and shoulder distraction in collegiate baseball pitchers.

A distraction force occurs at the shoulder joint in all throwing motions. At the professional level, the relationship between this force and pitching mechanics has been explained. Three-dimensional, high-speed (240 Hz) video data were collected on fastballs from 48 collegiate baseball pitchers. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing arm elbow and shoulder joints were calculated. Multiple linear regression analysis was used to investigate the relationships between shoulder distraction and pitching mechanics. Shoulder distraction stress averaged 81% body weight for the collegiate pitchers. The mean ball velocity was 81 mph. Ten parameters of pitching mechanics accounted for 89% of the variance in shoulder distraction. Two of the variables (maximum shoulder abduction torque and elbow angle at release) previously shown to affect shoulder distraction in professional baseball pitchers appear to be important for collegiate pitchers as well. These data provide a scientific basis for clinicians, athletes, and coaches to establish methods to reduce distraction force at the shoulder joint through modification of pitching mechanics.

Kinematics and kinetics of elite windmill softball pitching.

BACKGROUND: A significant number of time-loss injuries to the upper extremity in elite windmill softball pitchers has been documented. The number of outings and pitches thrown in 1 week for a softball pitcher is typically far in excess of those seen in baseball pitchers. Shoulder stress in professional baseball pitching has been reported to be high and has been linked to pitching injuries. Shoulder distraction has not been studied in an elite softball pitching population. HYPOTHESIS: The stresses on the throwing shoulder of elite windmill pitchers are similar to those found for professional baseball pitchers. STUDY DESIGN: Descriptive laboratory study. METHODS: Three-dimensional, high-speed (120 Hz) video data were collected on rise balls from 24 elite softball pitchers during the 1996 Olympic Games. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder were calculated. Multiple linear regression analysis was used to relate shoulder stress and pitching mechanics. RESULTS: Shoulder distraction stress averaged 80% of body weight for the Olympic pitchers. Sixty-nine percent of the variability in shoulder distraction can be explained by a combination of 7 parameters related to pitching mechanics. CONCLUSION: Excessive distraction stress at the throwing shoulder is similar to that found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper extremity kinematics and kinetics for elite softball pitchers has been established.

Differential phenotypic characteristics of heterogeneous cell population in the rabbit periosteum.

BACKGROUND: Periosteum and periosteum-derived progenitor cells have demonstrated the potential for stimulative applications in repair of various musculoskeletal tissues. It has been found that the periosteum contains mesenchymal progenitor cells that are capable of differentiating into either osteoblasts or chondrocytes, depending on the culture conditions. Anatomically, the periosteum is a heterogeneous multilayered membrane, consisting of an outer fibrous and an inner cambium layer. The present study was designed to elucidate the phenotypic characteristics of fibrous and cambium layer cells in vitro. METHODS: Using a sequential enzymatic digestion method, fibrous and cambium layer cells were harvested separately from periosteum-bone explants of the proximal tibia of 6-month-old New Zealand White rabbits. RESULTS: We found that the cells from each layer showed distinct phenotypic characteristics in a primary monolayer culture system. Specifically, the cambium cells demonstrated higher osteogenic characteristics (higher alkaline phosphatase and osteocalcin levels) than the fibrous cells. However, these differences diminished with time in vitro. INTERPRETATION: Our findings suggest that the periosteum has phenotypically distinct heterogeneous cell populations. Care must be taken in order to identify and distinguish the intrinsic phenotypes of the heterogeneous periosteum-derived cell types in vitro.