Use of Machine Learning to Predict Improvement After Hip Arthroscopy
The management of expectations is crucial when counseling patients undergoing treatment for a musculoskeletal injury or condition. In hip arthroscopy, this is especially critical when discussing with patients—including athletes seeking to return to play—their anticipated outcomes following surgical treatment for femoroacetabular impingement syndrome (FAIS).
In the latest issue of JBJS, Kunze et al. report on their investigative efforts to develop and internally validate machine learning algorithms that can yield patient-specific predictions of which athletes will reach clinically relevant improvement in function after arthroscopy for FAIS.
A total of 1,118 athletes, identified through a retrospective review of clinical registry data, met the inclusion criteria. The primary outcome was attaining the minimal clinically important difference (MCID) in the Hip Outcome Score-Sports Subscale (HOS-SS) at a minimum of 2 years postoperatively. Six machine learning algorithm models were tested.
The authors found that 23.1% of the athletes did not achieve the MCID for the HOS-SS. Six variables optimized algorithm performance, with the following cutoffs found to decrease the likelihood of achieving the MCID:
- Preoperative HOS-SS score of ≥58.3
- Tönnis grade of 1 (early osteoarthritis)
- Alpha angle of ≥67.1° on anteroposterior radiograph
- Body mass index (BMI) of >26.6 kg/m2
- Tönnis angle of >9.7° (indicating subtle instability or dysplasia)
- Patient age of >40 years
The elastic-net penalized logistic regression (ENPLR) model was the most accurate model in this study.
The findings suggest that patient selection is paramount to the ability to achieve clinically relevant improvements in outcomes for patients treated with arthroscopy for FAIS. Multiple studies have demonstrated that increasing arthritis level and age, along with BMI, are associated with inferior patient-reported outcomes. In addition, hip instability and increased Tönnis angle have been shown to be associated with worse outcomes following hip arthroscopy. A greater alpha angle indicates a larger “deformity” and thus the potential for more damage at the time of surgery that cannot be completely addressed with today’s surgical techniques. “Higher” preoperative HOS-SS (although on a scale of 0 to 100, 58 is not that high) may make it more difficult for a patient to achieve enough of an improvement in their outcome score to be considered as having attained the MCID.
The ENPLR model was converted into an open-source application, although as Kunze et al. point out, external validation is necessary before wider adoption of the application. Nonetheless, the model demonstrates the potential to help hip surgeons better educate our patients on expected outcomes and to assist with proper patient selection for the ever-evolving treatment of FAIS.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Co-author Kyle N. Kunze, MD discusses this study in an “Author Insights” video, found here.
What’s New in Sports Medicine 2021
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 14 subspecialties. Click here for a collection of all such OrthoBuzz Guest Editorial summaries.
This month, co-author Rachel M. Frank, MD summarizes the 5 most compelling findings from the >30 studies highlighted in the April 21, 2021 “What’s New in Sports Medicine.”
Anterior Cruciate Ligament (ACL)
–Two-year results from the STABILITY randomized controlled trial (RCT)1 comparing single-bundle, hamstring-autograft ACL reconstruction with or without lateral extra-articular tenodesis demonstrated a
4% graft failure in the tenodesis group versus 11% in the non-tenodesis group. Both groups had similar levels of sports activity at 2 years.
Meniscus
–A matched cohort comparison of 45 posterior medial meniscal root tears2 treated either nonoperatively, with partial meniscectomy, or with root repair found the following at a mean of 74 months:
- No significant between-group differences in patient-reported outcomes (IKDC and Tegner scores)
- Progression to arthroplasty in 60% of those who underwent partial meniscectomy, 27% of those treated nonoperatively, and 0% of those who underwent root repair
- Less arthritic progression on radiographs in the root-repair group relative to the other 2 groups
Rotator Cuff
–A multicenter Level-II study compared 96 patients with a rotator cuff tear who underwent nonoperative treatment with 73 similar patients who underwent a surgical procedure. At approximately 3 months, patients in the nonoperative group had significantly better outcomes, but after 1 to 2 years, surgical patients did better in terms of ASES and SPADI scores.
Hip Preservation
–A meta-analysis of 3 RCTs (n=650 patients)3 comparing physical therapy with hip arthroscopy for treating femoroacetabular impingement found the following:
- Greater improvement in the arthroscopy group (as measured with the International Hip Outcome Tool-33) at 10 months
- No between-group differences in 1 of the 3 RCTs at 1 or 2 years when the Hip Outcome Score-ADL and -Sports scales were used
The authors concluded that “hip arthroscopy had significantly superior short-term outcomes.”
Long Head of the Biceps Tendon
–A prospective RCT4 compared biceps tenodesis with biceps tenotomy in >100 patients with pathology of the long head of the biceps tendon. At the 2-year follow-up, the authors found no between-group differences in cramping, elbow flexion strength, or supination strength. The only significant difference was the incidence of a cosmetic Popeye deformity, which was associated with a 3.5 times higher risk after tenotomy.
References
- Getgood AMJ, et al. for the STABILITY Study Group. Lateral extra-articular tenodesis reduces failure of hamstring tendon autograft anterior cruciate ligament reconstruction: 2-year outcomes from the STABILITY study randomized clinical trial. Am J Sports Med.2020 Feb;48(2):285-97. Epub 2020 Jan 15.
- Bernard CD, Kennedy NI, Tagliero AJ, Camp CL, Saris DBF, Levy BA, Stuart MJ, Krych AJ. Medial meniscus posterior root tear treatment: a matched cohort comparison of nonoperative management, partial meniscectomy, and repair. Am J Sports Med.2020 Jan;48(1):128-32. Epub 2019 Nov 25.
- Dwyer T, Whelan D, Shah PS, Ajrawat P, Hoit G, Chahal J. Operative versus nonoperative treatment of femoroacetabular impingement syndrome: a meta-analysis of short-term outcomes. 2020 Jan;36(1):263-73.
- MacDonald P, Verhulst F, McRae S, Old J, Stranges G, Dubberley J, Mascarenhas R, Koenig J, Leiter J, Nassar M, Lapner P. Biceps tenodesis versus tenotomy in the treatment of lesions of the long head of the biceps tendon in patients undergoing arthroscopic shoulder surgery: a prospective double-blinded randomized controlled trial. Am J Sports Med.2020 May;48(6):1439-49. Epub 2020 Mar 30.
Day-of-Surgery Post-op Talks with Patients Worth the Effort
Personal communication goes a long way in establishing and cementing surgeon-patient relationships. I learned years ago that something as simple as giving patients my email address diminished their fear and anxiety because it gave them direct access to me. Now, due largely to the recent pandemic, more numerous and sophisticated forms of “telemedicine” have come to the forefront of health-care delivery.
In the February 3, 2020 issue of The Journal, Kingery et al. report results from a randomized controlled trial investigating whether brief day-of-surgery communications between surgeons and patients who underwent an outpatient sports-medicine procedure affected patient satisfaction scores. To find out, the researchers randomized 3 surgeons into 1 of 3 patient-communication modalities:
- No contact (standard of care)
- Phone call the evening after surgery
- Video call the evening after surgery
Satisfaction among the 250 participating patients was assessed at the first face-to-face postoperative visit using the standardized S-CAHPS questionnaire, which evaluates patient experiences before, during, and after an outpatient surgery. Patients also completed a 9-item questionnaire specifically designed for this study. The authors focused on the rate of “top-box” responses (the highest rating possible) in each of the 3 groups group.
Kingery et al. found that day-of-surgery postoperative communication between patients and surgeons, either by video or phone, significantly improved S-CAHPS top-box response rates relative to the no-contact group. Specifically, phone calls were associated with a 16.1 percentage point increase in the top-box response rate, while video calls were associated with a 17.8 percentage point increase. The authors also found that patients contacted by video or phone were more likely to recommend their surgeon and felt more informed than those who were not contacted.
Although the authors did not record the content or duration of the conversations in the 2 contact groups, these data strongly suggest that patients welcome day-of-surgery communication—and that such encounters improve patient satisfaction. I therefore think we all should consider leveraging technology, especially that which has arisen from the COVID pandemic, to help give our patients a better overall health-care experience. A few non-reimbursable minutes at the end of the day could have lasting, positive effects on both patients and us.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
History Counts–And It Needs to Be Complete
Joel L. Boyd, MD
It has often been shown that those who do not study history are doomed to repeat its mistakes. The Journal of Bone & Joint Surgery has a >130-year history, which we must continue to review. Understanding our history is so important that JBJS staff and trustees have invested in a 6-month project to get our history encapsulated and published on our website for continuous reference and reflection. The history of our journal contains mistakes—one stark example of which is promulgating the use of metal-on-metal arthroplasty.
But history is not complete until all the stories are told. Incomplete history is particularly evident with our North American native populations and individuals of African heritage. Here history is recorded with formerly conscious and now primarily unconscious (I hope) bias against accurately detailing the important contributions of native and Black citizens.
In the November 4, 2020 issue of The Journal, Dr. Joel Boyd does us great service by setting the record straight regarding the contributions of Black Canadians and Americans to the sport of ice hockey. (Our collective history in orthopaedics has particular relevance in sports.) Black athletes were on the ice at the sport’s very inception and in the early formation of competitive leagues. Dr. Boyd’s history, which focuses on the Black Hockey League of the Maritimes and Willie O’Ree, the “Jackie Robinson of hockey,” is replete with bias against acknowledging these contributions and against allowing non-Whites to compete for the sport’s highest trophies.
Let us all study these contributions, recognize their importance, and vow to be ever-vigilant for any bias, conscious or unconscious, in our thinking and conduct. May Dr. Boyd’s important exercise in completing this bit of history repeat itself in sport, science, and medicine across the board.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
What’s New in Sports Medicine 2020
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of OrthoBuzz summaries of these “What’s New” articles. This month, co-author Christopher Y. Kweon, MD selected the 5 most clinically compelling findings from the 40 studies summarized in the April 15, 2020 “What’s New in Sports Medicine.”
ACL Graft Choice
—A randomized controlled trial (RCT) comparing bone-tendon-bone autograft, quadrupled hamstring tendon autograft, and double-bundle hamstring autograft for ACL reconstruction in young adults found the following:
- No between-group differences in patient-reported quality-of-life scores at 5 years
- Significantly higher rates of traumatic graft reinjuries in the hamstring-tendon and double-bundle groups
- Relatively low (37%) return to preinjury level of activity for the entire population, with no significant between-group differences
Meniscal Repairs with Bone Marrow Venting
—A double-blinded RCT1 of patients with complete, unstable, vertical meniscal tears compared isolated meniscal repair to meniscal repair with a bone marrow venting procedure (BMVP). Meniscal healing, as assessed with second-look arthroscopy at a mean of 35 weeks, was 100% in the BMVP group and 76% in the control group (p = 0.0035). Secondary pain and function measures at 32 to 51 months were also better in the BMVP group.
Rotator Cuff Repair Rehab
—A multisite RCT2 among >200 patients who received arthroscopic repair of a full-thickness rotator cuff tear compared standard rehabilitation (patients wore a sling at all times except when performing prescribed exercises) and early mobilization (patients wore a sling only when needed for comfort). Early mobilizers showed significantly better forward flexion and abduction at 6 weeks, but no subjective or objective differences (including retear rate) were found at any other time points.
Remplissage for Anterior Shoulder Instability
—A systematic review3 of studies investigating arthroscopic Bankart repair with and without remplissage found significantly higher instability-recurrence rates with isolated Bankart repair. Overall, the addition of remplissage appears to yield better patient-reported function scores compared with isolated Bankart repair alone.
Syndesmotic Ankle Injuries
—A meta-analysis of 7 RCTs (335 patients)4 comparing dynamic versus static fixation for syndesmotic injuries of the ankle found that the overall risk of complications was significantly lower in the dynamic fixation group. Reoperation rates were similar in the two groups, but implant breakage or loosening was reduced with dynamic fixation devices. Compared with static fixation, the dynamic fixation group also had higher AOFAS scores and lower VAS scores at various time points.
References
- Kaminski R, Kulinski K, Kozar-Kaminska K, Wasko MK, Langner M, Pomianowski S. Repair augmentation of unstable, complete vertical meniscal tears with bone marrow venting procedure: a prospective, randomized, double-blind, parallel-group, placebo-controlled study. Arthroscopy.2019 May;35(5):1500-1508.e1. Epub 2019 Mar 20.
- Sheps DM, Silveira A, Beaupre L, Styles-Tripp F, Balyk R, Lalani A, Glasgow R, Bergman J, Bouliane M; Shoulder and Upper Extremity Research Group of Edmonton (SURGE). Early active motion versus sling immobilization after arthroscopic rotator cuff repair: a randomized controlled trial. Arthroscopy.2019 Mar;35(3):749-760.e2.
- Lazarides AL, Duchman KR, Ledbetter L, Riboh JC, Garrigues GE. Arthroscopic remplissage for anterior shoulder instability: a systematic review of clinical and biomechanical studies. Arthroscopy.2019 Feb;35(2):617-28. Epub 2019 Jan 3.
- Grassi A, Samuelsson K, D’Hooghe P, Romagnoli M, Mosca M, Zaffagnini S, Amendola A. Dynamic stabilization of syndesmosis injuries reduces complications and reoperations as compared with screw fixation: a meta-analysis of randomized controlled trials. Am J Sports Med.2019 Jun 12. [Epub ahead of print].
ACL Grafts: Diameter Does Matter, Sort Of
Clinical failure of anterior cruciate ligament (ACL) reconstructions continues to be a too-common scenario. The increasing incidence of ACL revision is due to a variety of factors, including greater intensity of postsurgical physical activity, technical issues, and anatomical influences of the proximal tibia and distal femur. Registries are important sources of data for ACL-related investigations, but I think they are most useful in clarifying experimental designs for more sophisticated clinical research.
In a cohort study in the October 16, 2019 issue of The Journal, Snaebjornsson et al. examined the influence of ACL graft diameter on the risk of revision surgery over 2 years in >18,000 subjects whose data resided in the national knee ligament registries of Sweden and Norway. The vast majority of those patients (92.8%) received a hamstring autograft, with 7.2% receiving a patellar tendon autograft. Overall, the 2-year rate of ACL revision was 2.63% for patellar tendon autografts and 2.08% for hamstring autografts, a statistically nonsignificant difference in relative risk.
However, the authors found an important correlation between graft diameter in the hamstring tendon cohort, with autografts <8 mm in diameter being associated with a higher risk of revision, compared with larger-diameter hamstring autografts. Additionally, patients treated with hamstring graft diameters of ≥9 mm or ≥10 mm had a lower risk of ACL revision surgery than those treated with patellar tendon grafts of any size.
One key limitation that should influence our interpretation of this study is a lack of detail regarding how compliant surgeons were intraoperatively with the use of the measurement device that is depicted in the manuscript and shown above. In addition, the limitations of registry data did not permit the authors to adjust for postsurgical exposures, such as return to sport, the increasing intensity of which makes rerupture more likely. Additional relevant information that would have aided interpretation of the findings includes the relative size of the tibia and femur, lateral condyle size and shape, and proximal tibial slope.
Despite these limitations, this study should prompt further research that uses robust clinical designs to more fully investigate the impact of graft diameter on ACL rerupture rates.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
April 2019 Article Exchange with JOSPT
In 2015, JBJS launched an “article exchange” collaboration with the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) to support multidisciplinary integration, continuity of care, and excellent patient outcomes in orthopaedics and sports medicine.
During the month of April 2019, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “Repair of the Ulnar Collateral Ligament of the Elbow: Rehabilitation Following Internal Brace Surgery.”
In this Clinical Commentary based on the authors’ experience with >350 cases, Wilk et al. describe the rehabilitation process used for patients following UCL repair with an “internal brace.” This recent surgical advance in managing incomplete UCL tears enhances elbow joint stability while the ligament is healing.
Weight Training-Induced Bilateral Knee Dislocation
You know you’re having a bad day at the gym when both your knees dislocate during a leg-press workout. That is what happened to a 44-year-old male recreational weight lifter who “locked out” both his knees while trying to press 1,100 lbs. This unusual case is described in the latest issue of JBJS Case Connector.
Knee joint dislocations are true emergencies because of the potential for concomitant neurovascular injury. This patient was transferred to a tertiary academic hospital for emergency closed reduction and application of knee-spanning external fixators. Although both tibiae were dislocated anteriorly, both lower extremities were neurovascularly intact.
One month after the initial injury, the external fixators were removed and the knees were placed in bilateral hinged braces. MRI performed shortly thereafter revealed tears of multiple ligaments and distal popliteus tendon tears in both knees. At 4 months postinjury, the patient underwent left-side ACL reconstruction, PCL reconstruction, FCL repair and reconstruction, popliteal reconstruction with allograft, and a popliteofibular ligament reconstruction. Seven months after that, he underwent similar procedures on the right side.
At the most recent postsurgical follow-up, 17 months after the initial injury, the range of motion in both knees was 0° to 130°, and the patient was able to participate in straight line running, squats, and cycling.
The authors emphasize that any locking of the knees results in 5° to 10° of hyperextension, which places an increased load across the ACL. Add to that the heavy weight and the abrupt increase in velocity at the extreme range of motion, and you have a recipe for serious injury. The authors conclude that “the risk of knee dislocation can be reduced by avoiding locking and hyperextension of the knees during any type of leg press or squatting exercise.”
For more information about JBJS Case Connector, watch this video featuring JBJS Editor in Chief Dr. Marc Swiontkowski.
Arthroscopy Beats PT for FAI at 8 Months
OrthoBuzz occasionally receives posts from guest bloggers. In response to a recent BMJ study, the following commentary comes from Matthew R. Schmitz, MD, FAOA.
Femoroacetabular impingement (FAI) syndrome continues to be a hot topic in the orthopaedic community. The first two decades of this century have seen huge increases in the number of hip arthroscopies performed in the US and UK,1,2 most of those to treat FAI. In the February 7, 2019 issue of BMJ, Palmer et al., reporting on behalf of the Femoroacetabular Impingement Trial (FAIT), published preliminary findings from a multicenter randomized controlled trial comparing arthroscopic hip surgery to activity modification and physiotherapy for symptomatic FAI.3
The trial randomized 222 patients with a clinical diagnosis of FAI into each cohort (110 in the physiotherapy group and 112 in the arthroscopy group). Follow-up assessments were performed by clinicians blinded to the treatment arm, and attempts were made to standardize both interventions. The participants will eventually be followed for 3 years, but this early report evaluated outcomes 8 months after randomization, with follow-up data available for >80% of patients in both groups.
Baseline characteristics with regard to demographics, radiographic findings, and clinical measurements were similar between the two groups. After adjusting for multiple potential confounders, the authors found that the mean Hip Outcomes Score Activities of Daily Living (HOS ADL) was 10 points higher in the arthroscopy group than in the physiotherapy group, exceeding the prespecified minimum clinically important difference (MCID) of 9 points. The MCID was reached in 51% of surgical patients compared to 32% in the therapy cohort. In addition, the patient acceptable symptomatic state (PASS)—defined as a HOS ADL ≥87 points—was achieved in 48% of surgical patients and only 19% of therapy patients. Relative to the physiotherapy group, the arthroscopic group also had better hip flexion and superior results in a variety of commonly used hip patient-reported outcomes scores.
The 8-month data from this study show that there is a real improvement in patient function and reported outcomes from arthroscopic management for FAI. It will be important, however, to follow these patients for the entire 3 years of the FAIT study to show whether these improvements persist. It should also be emphasized that only half of the patients treated with surgical management achieved MCID at the 8-month point. That finding supports what I tell patients in my young-adult hip-preservation clinics, which seems relevant as baseball season starts: There are rarely any home runs in arthroscopic hip surgery. There are mainly singles and doubles that we hope to stretch into doubles and triples. Still, it appears that even those base hits with arthroscopic surgery are better than the physiotherapy alternative—at least in the early innings of the game.
Matthew R. Schmitz, MD, FAOA is an orthopaedic surgeon specializing in adolescent sports and young adult hip preservation at the San Antonio Military Medical Center in San Antonio, TX. He is also a member of the JBJS Social Media Advisory Board.
References
- Maradit Kremers H, Schilz SR, Van Houten HK et al. Trends in Utilization and Outcomes of Hip Arthrocopy in the United States Between 2005 and 2013. J Arthroplasty 2017; 32:750-5.
- Palmer AJ, Malak TT, Broomfield J, et al. Past and projected temporal trends in arthroscopic hip surgery in England between 2002 and 2018. BMJ Open Sport Exerc Med 2016;2:e000082
- Palmer AJ, Gupta VA, Fernquest S, et al. Arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of symptomatic femoroacetabular impingement: multicenter randomized controlled trial. BMJ 2019; 364:l185
Education, Guidelines, Willingness: Keys to Changing Opioid-Prescribing Habits
When planning for any type of surgical procedure, the orthopaedist considers many patient and injury-specific variables. With a distal radius fracture, for example, the main goal of the surgery—anatomic reconstruction of the distal radius—remains constant. However, there are numerous other variables (fracture morphology and patient age, just to name 2) that have to be considered to achieve that goal. Yet, when it comes to postoperative pain control, I imagine that most orthopaedic surgeons prescribe the same amount of opioids to almost every patient undergoing an open reduction/internal fixation of a distal radius fracture, regardless of unique patient characteristics. Our medical mantra that “no two patients are the same” seems to fall by the wayside when it comes to postoperative pain control.
This disconnect is what I thought about while reading the article by Stepan et al. in the January 2, 2019 issue of The Journal. The authors’ institution developed and disseminated to all prescribers a 1-hour opioid education program and consensus-based postoperative opioid prescription guidelines. They then compared the number of opioid pills and total oral morphine equivalents prescribed after 9 ambulatory procedures within 3 subspecialty services (sports medicine, hand, and foot and ankle) prior to and after implementation of the guidelines. Stepan et al. found a significant decrease in the amount of narcotics prescribed after 6 of the 9 surgery types after implementation of the guidelines. Over the course of a year, those decreases would have equaled about 30,000 fewer opioid pills!
Interestingly, there was no significant post-guideline decrease in opioid prescribing after any of the 3 foot-and-ankle procedures. The authors attribute that finding to the slow adoption of the guidelines due to adherence to previously developed pain-management recommendations in this subspecialty.
It has become apparent that we tend to overprescribe opioids postoperatively (see related OrthoBuzz post). This study supports previous data showing that prescription guidelines can be useful in decreasing the amount of postoperative narcotics prescribed to patients, while maintaining adequate pain management and good levels of patient satisfaction. While further work in developing educational tools and procedure-specific “standards” to help surgeons guide their postoperative prescribing practices would be useful, a surgeon’s mindfulness is equally important. We need first to recognize that orthopaedic surgeons tend to overprescribe postoperative opioids—and second, we must be willing to change our habits. Without both awareness and willingness, the best guidelines and recommendations will be ignored, and an opportunity for us to help curb the opioid crisis in our country will be wasted.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
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