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Camp, Christopher L.

0000-0003-3058-7327

Mayo Clinic

Mayo Clinic

Citations 242

Osteochondral Allograft Transplantation for the Unstable Capitellar Osteochondritis Dissecans Lesion: An Anconeus Preserving Approach
Feroe, Aliya G. , Langhans, Mark T. , Sanchez-Sotelo, Joaquin, Sánchez‐Sotelo, Joaquín , Morrey, Mark E. , Camp, Christopher L.

Video Journal of Sports Medicine | July 11, 2023 | Volume: 3 | Issue: 4 | Pages: No page available

10.1177/26350254231173701 Get It

Background: Osteochondritis dissecans (OCD) of the capitellum can be a disabling condition that typically affects adolescent, overhead athletes. To date, a variety of different surgical treatment options have been described. Indications: Surgical indications for osteochondral allograft transplantation (OCA) for capitellar OCD lesions include failure of nonsurgical management or prior surgery and unstable, full-thickness lesions of almost any size affecting both bone and cartilage. The anconeus preserving approach specifically provides wide access to nearly the entire capitellum and can be used for lesions in almost any location. Technique Description: The anconeus preserving approach for OCA utilizes the interval between the anconeus and the ulna. With the patient positioned supine and the elbow flexed on an arm table, an incision is made approximately 1 cm lateral to the olecranon and is carried down to the fascia. Electric cautery is used to dissect the interval between the ulna and the anconeus. The anconeus is elevated off the ulna and retracted laterally to expose the underlying joint capsule. An L-shaped capsulotomy is performed over the center of the capitellum, just proximal to the annular ligament of the radial head. A pin is placed into the center of the lesion, perpendicular to the capitellum. A cannulated reamer 0.5 mm smaller than the lesion is used to ream the lesion to a depth of approximately 5 mm. Depth measurements are taken at all 4 poles of the defect. About 3 cc of bone marrow aspirate harvest is then obtained from the ulna using a cannulated needle. The oscillating saw is used to cut the graft to size using the prior measurements. The bone marrow aspirate is placed onto the osseous side of the graft before the osteochondral graft is impacted into the recipient site. The capsulotomy is then closed, and the anconeus is repaired back to the ulna. Postoperatively, patients begin range of motion as soon as tolerated, initiate strengthening at 6 weeks, and initiate return-to-sport programming at 3 months. Results: Lesions treated with OCA typically demonstrate improvement in all outcome measures, including functional scores, graft incorporation, articular surface congruity, and return-to-sport. Complications and graft failure is rare. Discussion/Conclusion: OCA using an anconeus preserving approach is a reliable option for surgical management of unstable OCD lesions. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
Machine learning can accurately predict risk factors for all‐cause reoperation after ACLR: creating a clinical tool to improve patient counseling and outcomes
Johnson, Quinn J. , Jabal, Mohamed Sobhi , Arguello, Alexandra M. , Jurgensmeier, Kevin , Levy, Bruce A. , Krych, Aaron J. , Jabal, Mohamed S, Krych, Aaron J , Jurgensmeier, Kevin , Lu, Yining , Camp, Christopher L.

Knee Surgery, Sports Traumatology, Arthroscopy | July 6, 2023 | Volume: 31 | Issue: 10 | Pages: 4099-4108

10.1007/s00167-023-07497-7 Get It

AbstractPurposeIdentifying predictive factors for all‐cause reoperation after anterior cruciate ligament reconstruction could inform clinical decision making and improve risk mitigation. The primary purposes of this study are to (1) determine the incidence of all‐cause reoperation after anterior cruciate ligament reconstruction, (2) identify predictors of reoperation after anterior cruciate ligament reconstruction using machine learning methodology, and (3) compare the predictive capacity of the machine learning methods to that of traditional logistic regression.MethodsA longitudinal geographical database was utilized to identify patients with a diagnosis of new anterior cruciate ligament injury. Eight machine learning models were appraised on their ability to predict all‐cause reoperation after anterior cruciate ligament reconstruction. Model performance was evaluated via area under the receiver operating characteristics curve. To explore modeling interpretability and radiomic feature influence on the predictions, we utilized a game‐theory‐based method through SHapley Additive exPlanations.ResultsA total of 1400 patients underwent anterior cruciate ligament reconstruction with a mean postoperative follow‐up of 9 years. Two‐hundred and eighteen (16%) patients experienced a reoperation after anterior cruciate ligament reconstruction, of which 6% of these were revision ACL reconstruction. SHapley Additive exPlanations plots identified the following risk factors as predictive for all‐cause reoperation: diagnosis of systemic inflammatory disease, distal tear location, concomitant medial collateral ligament repair, higher visual analog scale pain score prior to surgery, hamstring autograft, tibial fixation via radial expansion device, younger age at initial injury, and concomitant meniscal repair. Pertinent negatives, when compared to previous studies, included sex and timing of surgery. XGBoost was the best‐performing model (area under the receiver operating characteristics curve of 0.77) and outperformed logistic regression in this regard.ConclusionsAll‐cause reoperation after anterior cruciate ligament reconstruction occurred at a rate of 16%. Machine learning models outperformed traditional statistics and identified diagnosis of systemic inflammatory disease, distal tear location, concomitant medial collateral ligament repair, higher visual analog scale pain score prior to surgery, hamstring autograft, tibial fixation via radial expansion device, younger age at initial injury, and concomitant meniscal repair as predictive risk factors for reoperation. Pertinent negatives, when compared to previous studies, included sex and timing of surgery. These models will allow surgeons to tabulate individualized risk for future reoperation for patients undergoing anterior cruciate ligament reconstruction.Level of evidenceIII.
Surgical Technique for the Latarjet Procedure Using Non-Cannulated Screws
Nauert, Richard F. , Yu, Kristin E. , Camp, Christopher L.

Video Journal of Sports Medicine | July 5, 2023 | Volume: 3 | Issue: 4 | Pages: No page available

10.1177/26350254231161558 Get It

Background: The Latarjet procedure is effective for patients with anterior glenohumeral instability with substantial glenoid bone loss due to its triple blocking effect. Indications: Indications include high-risk patients with recurrent anterior glenohumeral instability with any glenoid bone loss or low-risk patients with 15% to 30% glenoid bone loss. Technique Description: An incision is made lateral to the coracoid and the deltopectoral interval is established. The pectoralis minor is released medially off the coracoid and the coracoacromial (CA) ligament is released close to the acromion. The coracoid is cut with a right-angle saw and the inferior coracoid is decorticated with a burr. Two holes are pre-drilled in the coracoid. The subscapularis is split between the upper two-thirds and lower one-third with the arm in external rotation. The capsule is split vertically at the joint line and the humeral head is retracted. The anterior glenoid is decorticated with a burr, and a hole is drilled inferiorly. The depth is measured and added to the depth of the inferior bone block hole. A fully threaded 3.5-mm solid stainless steel screw is placed in the inferior hole. Care is taken to ensure that the lateral border of the bone block is flush with the articular margin. This is repeated for the superior hole. A 1.8-mm knotless suture anchor is placed between the screws. The repair stitch is passed through the capsule and loaded onto the anchor and tensioned. The CA ligament is laid over the capsule and repaired. The subscapularis split is repaired side to side and the wound is closed in layers. Results: High return-to-sport rates, including at the same level of play, have been observed among young competitive athletes with significant glenoid bone loss who underwent a Latarjet, with similarly favorable results in older patients. Ninety-day complication rates have been reported around 9%, 5% of which constituted graft or hardware failures. Discussion/Conclusion: The Latarjet procedure is an effective option for indicated patients with anterior glenohumeral instability and may be enhanced with solid screws, proper anatomic technique, and capsulolabral repair augmentation. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
Surgical Stabilization for Recurrent Patellar Instability in Competitive Wrestlers: Outcomes, Reoperations, and Return to Play at 6-Year Mean Follow-up
Feroe, Aliya G. , Smith, John-Rudolph H. , Stuart, Michael J. , Camp, Christopher L. , Krych, Aaron J. , Smith, John R. , Marigi, Erick M. , Stuart, Michael J , Camp, Christopher L. , Krych, Aaron J , Smith, John-Rudolph , Hevesi, Mario

The American Journal of Sports Medicine | June 29, 2023 | Volume: 51 | Issue: 10 | Pages: 2608-2616

10.1177/03635465231182143 Get It

Background: The extent to which recurrent patellar instability (RPI) affects wrestlers has not been thoroughly examined. Purpose: To assess return to wrestling (RTW), patient-reported outcomes, and reoperation rates after patellofemoral stabilization surgery (PFSS) for RPI in a cohort of competitive wrestlers. Study Design: Cohort study; Level of evidence, 3. Methods: All competitive wrestlers with a history of RPI and subsequent PFSS performed at a single institution between 2000 and 2020 were identified. Primary PFSS procedures included medial patellofemoral (MPFL) reconstruction (n = 31; 50%); MPFL repair (n = 22; 35.5%); or other PFSS (n = 9; 14.5%), such as tibial tubercle osteotomy, lateral retinacular release, and/or medial retinacular reefing. Exclusion criteria included revision PFSS or concomitant anterior cruciate ligament reconstruction or multiligament knee injury. Surgical failure was defined as subsequent patellar dislocation despite operative management or need for secondary PFSS. Results: Ultimately, 62 knees in 56 wrestlers with a mean age of 17.0 years (range, 14.0-22.8 years) were included at a mean follow-up of 6.6 years (range, 2.0-18.8 years). RTW occurred in 55.3% of wrestlers at a mean ± SD 8.8 ± 6.7 months. Among PFSS types, no differences were observed in rates of RTW ( P = .676), postoperative pain ( P = .176), Tegner activity level ( P = .801), International Knee Documentation Committee ( P = .378), Lysholm ( P = .402), or Kujala scores ( P = .370). RPI was the most common postoperative complication (n = 13; 21.0%). MPFL reconstruction had the lowest rate of RPI (6.5% vs 27.3% [repair] vs 55.6% [other]; P = .005) and surgical failure (9.7% vs 31.8% [repair] vs 55.6% [other]; P = .008). Kaplan-Meier survivorship free from surgical failure of the entire cohort was 91.9% at 1 year, 77.7% at 5 years, and 65.7% at 15 years. MPFL reconstruction had the highest survivorship when compared with MPFL repair and other PFSS up to 10 years after the index surgery (90.3% vs 64.1% vs 27.8%; P = .048). Conclusion: RPI remains a concern for competitive wrestlers after PFSS. MPFL reconstruction may serve as a more durable surgical treatment option with lower rates of RPI and failure when compared with other PFSS procedures at up to 10 years after surgery.
Management of Partial-Thickness Tears of the Distal Bicep Tendon: Evaluation of 111 Patients With 10-Year Follow-up
Till, Sara E., Wilbur, Ryan R. , Song, Bryant M. , Reinholz, Anna K., Johnson, Adam C. , Sanchez-Sotelo, Joaquin, Tagliero, Adam J. , Sánchez‐Sotelo, Joaquín , Barlow, Jonathan D. , Camp, Christopher L.

Orthopaedic Journal of Sports Medicine | June 16, 2023 | Volume: 11 | Issue: 6 | Pages: No page available

10.1177/23259671231169202 Get It

Background: There is a paucity of research on the management of partial-thickness tears of the distal bicep tendon, and even less is known about the long-term outcomes of this condition. Purpose: To identify patients with partial-thickness distal bicep tendon tears and determine (1) patient characteristics and treatment strategies, (2) long-term outcomes, and (3) any identifiable risk factors for progression to surgery or complete tear. Study Design: Case-control study; Level of evidence, 3. Methods: A fellowship-trained musculoskeletal radiologist identified patients diagnosed with a partial-thickness distal bicep tendon tear on magnetic resonance imaging between 1996 and 2016. Medical records were reviewed to confirm the diagnosis and record study details. Multivariate logistic regression models were created using baseline characteristics, injury details, and physical examination findings to predict operative intervention. Results: In total, 111 patients met inclusion criteria (54 treated operatively, 57 treated nonoperatively), with 53% of tears in the nondominant arm and a mean follow-up time after surgery of 9.7 ± 6.5 years. Only 5% of patients progressed to full-thickness tears during the study period, at a mean of 35 months after the initial diagnosis. Patients who were nonoperatively treated were less likely to miss time from work (12% vs 61%; P < .001) and missed fewer days (30 vs 97 days; P < .016) than those treated surgically. Multivariate regression analyses demonstrated increased risk of progression to surgery with older age at initial consult (unit odds ratio [OR], 1.1), tenderness to palpation (OR, 7.5), and supination weakness (OR, 24.8). Supination weakness at initial consult was a statistically significant predictor for surgical intervention (OR, 24.8; P = .001). Conclusion: Clinical outcomes were favorable for patients regardless of treatment strategy. Approximately 50% of patients were treated surgically; patients with supination weakness were 24 times more likely to undergo surgery than those without. Progression to full-thickness tear was a relatively uncommon reason for surgical intervention, with only 5% of patients progressing to full-thickness tears during the study period and the majority occurring within 3 months of initial diagnosis.
Repair of the Medial Ulnar Collateral Ligament of the Elbow With Internal Brace Augmentation
Nauert, Richard F. , Yu, Kristin E. , Camp, Christopher L.

Video Journal of Sports Medicine | May 26, 2023 | Volume: 3 | Issue: 3 | Pages: No page available

10.1177/26350254231165317 Get It

Background: The medial ulnar collateral ligament (MUCL) is the primary restraint to valgus force across the elbow during throwing. The incidence of MUCL continues to rise, and injuries are common in overhead throwing athletes often leading to elbow pain and instability. While MUCL reconstruction remains the gold standard for high-level throwing athletes with midsubstance tears, MUCL repair remains an option for select athletes and affords good functional outcomes with quicker return to sport compared with reconstruction. Indications: Indications for MUCL repair include acute injuries, proximal or distal avulsions, young and lower demand athletes, non-throwing athletes, or older athletes who may be nearing retirement. Technique Description: An incision is made over the medial elbow from the medial epicondyle to the sublime tubercle. Dissection is carried down to fascia which is split in line with its fibers. The flexor pronator muscle group is bluntly divided, and the ligament exposed. Care is taken to identify and dissect the native ligament. The avulsed portion of the ligament is secured with a 0 FiberWire suture in a running locked whipstitch fashion. The footprint of the avulsed ligament is gently debrided and prepared using a scalpel. The 0-FiberWire suture tails are then loaded onto a suture anchor preloaded with suture tape. This is then secured at the footprint of the ligament. The FiberWires are cut, and the suture tape is then pulled back over the native ligament and fixed at the other attachment site for the ligament. 0-Vicryl sutures are then used to suture the internal brace to the underlying ligament so the construct would move as a single unit. Results: Biomechanical testing has demonstrated that MUCL repair with internal brace augmentation has similar time-zero failure strength when compared with the original Jobe reconstruction technique while also having greater resistance to gapping. In addition, recent literature has shown that well-selected patients can have excellent functional outcomes and quicker return to sport with MUCL repair as opposed to reconstruction. Discussion: Medial ulnar collateral ligament repair with internal brace augmentation can be a successful treatment in the appropriately indicated athlete to allow for good functional results and quicker return to sport. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
Predicting the Risk of Posttraumatic Osteoarthritis After Primary Anterior Cruciate Ligament Reconstruction: A Machine Learning Time-to-Event Analysis
Lu, Yining , Reinholz, Anna K., Till, Sara E., Kalina, Sydney V., Saris, Daniël B.F. , Lu, Yining , Camp, Christopher L. , Stuart, Michael J.

The American Journal of Sports Medicine | May 12, 2023 | Volume: 51 | Issue: 7 | Pages: 1673-1685

10.1177/03635465231168139 Get It

Background: There is a significant long-term risk of posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament reconstruction (ACLR). Elucidating the risk factors and successfully identifying at-risk patients is challenging. Purpose/Hypothesis: The purpose of this study was to produce machine learning survival models that can identify (1) patients at risk of symptomatic PTOA and (2) patients who are at risk of undergoing total knee arthroplasty (TKA) after ACLR. It was hypothesized that these models would outperform traditional Kaplan-Meier estimators. Study Design: Case-control study; Level of evidence, 3. Methods: A geographic database was used to identify patients undergoing ACLR between 1990 and 2016 with a minimum 7.5-year follow-up. Models were used to analyze various factors to predict the rate and time to (1) symptomatic osteoarthritis and (2) TKA using random survival forest (RSF) algorithms. Performance was measured using out-of-bag (OOB) c-statistic, calibration, and Brier score. The predictive performances of the RSF models were compared with Kaplan-Meier estimators. Model interpretability was enhanced utilizing global variable importance and partial dependence curves. Results: A total of 974 patients with ACLR and a minimum follow-up of 7.5 years were included; among these, 215 (22.1%) developed symptomatic osteoarthritis, and 25 (2.6%) progressed to TKA. The RSF algorithms achieved acceptable good to excellent predictive performance for symptomatic arthritis (OOB c-statistic, 0.75; Brier score, 0.128) and progression to TKA (OOB c-statistic, 0.89; Brier score, 0.026), respectively. Significant predictors of symptomatic PTOA included increased pain scores, older age, increased body mass index, increased time to ACLR, total number of arthroscopic surgeries before the diagnosis of arthritis, positive pivot-shift test after reconstruction, concomitant chondral injury, secondary meniscal tear, early (<250 days) or delayed (>500 days) return to sports or activity, and use of allograft. Significant predictors for TKA included older age, increased pain scores, total number of arthroscopic surgeries, high-demand activity/occupation, hypermobility, higher body mass index, systemic inflammatory disease, increased time to surgery, early (<250 days) or delayed (>500 days) return to sports or activity, and midsubstance tears. The Brier score over time revealed that RSF models outperformed traditional Kaplan-Meier estimators. Conclusion: Machine learning survival models were used to reliably identify patients at risk of developing symptomatic PTOA, and these models consistently outperformed traditional Kaplan-Meier estimators. Strong predictors for the development of PTOA after ACLR included increased pain scores at injury and postoperative visit, older age at injury, total number of arthroscopic procedures, positive postoperative pivot-shift test, and secondary meniscal tear.
Patients Aged >50 Years With Anterior Shoulder Instability Have a Decreased Risk of Recurrent Dislocation After Operative Treatment Compared With Non‐Operative Treatment
Smartt, Anne A. , Wilbur, Ryan R. , Song, Bryant M. , Krych, Aaron J. , Okoroha, Kelechi R. , Camp, Christopher L. , Okoroha, Kelechi, Camp, Christopher L. , Krych, Aaron J , Barlow, Jonathan D.

Arthroscopy, Sports Medicine, and Rehabilitation | May 6, 2023 | Volume: 5 | Issue: 3 | Pages: No page available

10.1016/j.asmr.2023.03.014 Get It

Purpose To compare the clinical outcomes of operative and nonoperative management, identify risk factors for recurrent instability, and identify risk factors for progression to surgery after failed nonoperative management for patients with first‐time anterior shoulder dislocation after the age of 50 years. Methods An established geographic medical record system was used to identify patients who experienced a first‐time anterior shoulder dislocation after the age of 50 years. Patient medical records were reviewed to identify treatment decisions and outcomes of interest, including rates of frozen shoulder and nerve palsy, progression to osteoarthritis, recurrent instability, and progression to surgery. Outcomes were evaluated using Chi‐square tests and survivorship curves were generated using Kaplan‐Meier methods. A Cox model was developed to evaluate for potential risk factors of recurrent instability and progression to surgery after an initial trail of at least 3 months of nonoperative treatment. Results 179 patients were included with a mean follow‐up of 11 years. 14% ( n = 26) underwent early surgery within 3 months and 86% ( n = 153) were initially treated nonoperatively. Mean age (59 years), was similar for both groups, but those that underwent early surgery had an increased rate of full‐thickness rotator cuff tears (82% vs 55%; P = .01), labral tears (24% vs 8.0%; P = .01), and humeral head fracture (23% vs 8.5%; P = .03). When comparing the early surgery group to the nonoperative group, there were similar rates of persistent moderate‐severe pain (19% vs 17%; P = .78) and frozen shoulder (8 vs 9%, respectively; P = .87) at final follow‐up. Although nerve palsy (19% vs 8%; P = .08) and progression to osteoarthritis (20% vs 14%; P = .40) were more common in surgical patients, they experienced lower rates of recurrent instability after surgical intervention (0% vs 15%; P = .03) compared to nonoperatively treated patients. Increasing number of instability events prior to presentation was the greatest risk factor for recurrent instability (HR 232; P < .01). Fourteen percent ( n = 21) failed initial nonoperative treatment and proceeded to surgical intervention at an average of 4.6 years after the initial instability event, and the greatest risk factors for progression to surgery were recurrent instability (HR 3.41; P < .01). Conclusions Although the majority of patients >50 years that experience ASI are treated nonoperatively, those that require surgery tend to have more significant injury pathology, a lower risk of recurrent instability after surgery, but a higher progression to osteoarthritis compared to patients that do not require surgical intervention. There was no difference in pain severity at final follow‐up, rates of frozen shoulder or nerve palsy between patients who underwent initial nonoperative treatment after instability and those who underwent surgery. A history of multiple instability episodes prior to presentation was the greatest predictor of recurrent instability and failure of nonoperative treatment and progression to surgery. Level of Evidence Level III, retrospective cohort study.
Improved Yet Varied Clinical Outcomes Observed With Comparison of Arthroscopic Superior Capsular Reconstruction Versus Arthroscopy‐Assisted Lower Trapezius Transfer for Patients With Irreparable Rotator Cuff Tears
Marigi, Erick M. , Jackowski, Jacob R., Barlow, Jonathan D. , Morrey, Mark E. , Camp, Christopher L. , Sánchez‐Sotelo, Joaquín , Elahi, Muhammad A , Barlow, Jonathan, Sanchez-Sotelo, Joaquin, Sanchez-Sotelo, J. , Camp, Christopher L. , Marigi, Erick , Barlow, Jonathan D , Morrey, Mark E , Elahi, Muhammad A.

Arthroscopy | May 2, 2023 | Volume: 39 | Issue: 10 | Pages: 2133-2141

10.1016/j.arthro.2023.04.012 Get It

Purpose To evaluate the outcomes of arthroscopic superior capsular reconstruction (SCR) and arthroscopy‐assisted lower trapezius tendon transfer (LTT) for posterosuperior irreparable rotator cuff tears (IRCTs). Methods Over an almost 6‐year period (October 2015 to March 2021), all patients who underwent IRCT surgery with a minimum 12‐month follow‐up period were identified. For patients with a substantial active external rotation (ER) deficit or lag sign, LTT was preferentially selected. Patient‐reported outcome scores included the visual analog scale (VAS) pain score, strength score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, Single Assessment Numeric Evaluation (SANE) score, and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score. Results We included 32 SCR patients and 72 LTT patients. Preoperatively, LTT patients had more advanced teres minor fatty infiltration (0.3 vs 1.1, P = .009), a higher global fatty infiltration index (1.5 vs 1.9, P = .035), and a higher presence of the ER lag sign (15.6% vs 48.6%, P < .001). At a mean follow‐up of 2.9 ± 1.3 years (range, 1.0‐6.3 years), no differences in patient‐reported outcome scores were observed. Postoperatively, SCR patients had a lower VAS score (0.3 vs 1.1, P = .017), higher forward elevation (FE) (156° vs 143°, P = .004), and higher FE strength (4.8 vs 4.5, P = .005) and showed greater improvements in the VAS score (6.8 vs 5.1, P = .009), FE (56° vs 31°, P = .004), and FE strength (1.0 vs 0.4, P < .001). LTT patients showed greater improvement in ER (17° vs 29°, P = .026). There was no statistically significant between‐cohort difference in complication rate (9.4% vs 12.5%, P = .645) or reoperation rate (3.1% vs 10%, P = .231). Conclusions With adequate selection criteria, both SCR and LTT provided improved clinical outcomes for posterosuperior IRCTs. Additionally, SCR led to better pain relief and restoration of FE whereas LTT provided more reliable improvement in ER. Level of Evidence Level III, treatment study with retrospective cohort comparison.
Are 4D Motion Sensors Valid and Reliable for Studying Baseball Pitching?
Loushin, Stacy R. , Verhoeven, Martijn, Christoffer, Daniel J., Camp, Christopher L. , Kaufman, Kenton R.

The American Journal of Sports Medicine | April 17, 2023 | Volume: 51 | Issue: 6 | Pages: 1608-1614

10.1177/03635465231166423 Get It

Background: Baseball pitching injuries are on the rise. Inertial measurement units (IMUs) provide immediate feedback to players and coaches, allowing for collection outside of the traditional laboratory setting with real-world application. The 4D Motion system provides kinematics throughout the pitching motion and may be beneficial for individualized programs in the throwing athlete. A systematic analysis of these sensors has not been completed. Purpose: To evaluate the validity of the 4D Motion IMU system for analyzing the baseball pitching motion compared with marker-based motion capture, and evaluate the internal reliability and consistency of the device. Study Design: Controlled laboratory study. Methods: Ten high school pitchers participated in this study (10 male; 9 right-hand dominant; mean age, 16.6 ± 1.3 years; mean body mass index, 24.1 ± 3.9). Participants were simultaneously outfitted with six 4D Motion IMU sensors and retroreflective markers. The pitchers threw fastballs at maximum effort off a mound at the standard height and distance. A comparison was made between the IMUs and corresponding motion capture values for shoulder external rotation, elbow flexion, chest extension, pelvis and chest rotation velocity, and rotation acceleration. Results: Significant differences were found for 5 of 7 metrics analyzed. The IMU overreported most metrics, except for elbow flexion and pelvis rotation angular acceleration, where both positive and negative errors were observed. The root mean square error and percentage errors indicated smaller discrepancies for chest extension (4°± 5°) and pelvis (38 ± 19 deg/s) and chest (96 ± 42 deg/s) rotation velocity, with elbow flexion having the largest variance (21°± 9°). Conclusion: The values of the 4D Motion IMU system should not be considered equivalent when compared with marker-based motion capture studies. The system lacked internal consistency and reliability, with angular velocities being the most consistent. Caution should be used when using the metrics provided by an IMU-based system for individualized monitoring. Clinical Relevance: If found valid and reliable, IMUs could be used for longitudinal workload monitoring, individualized throwing and rehabilitation programs, and ultimately injury prevention. This study demonstrates that the data obtained from a 4D Motion system using Gen 3 sensors are not equivalent to the data obtained from a marker-based motion capture system.