Knee Injuries and Associated Risk Factors in National Basketball Association Athletes

Purpose

To determine structural knee injury rates and to identify risk factors and the number of games missed associated with these injuries in National Basketball Association (NBA) players from the 2015 to 2020 seasons.

Methods

Publicly available player records of active NBA players between the 2015 and 2020 seasons (excluding the shortened 2019 season) were reviewed to identify players with a knee injury associated with missing one or more games. Player demographics, anthropometric measurements, statistics, injury characteristics, and history of other lower-extremity injuries were recorded. We sought factors associated with having a structural knee injury in bivariate analysis and multivariable logistic regression. Negative binomial regression was conducted to evaluate factors associated with the total number of games missed.

Results

Two hundred twelve players (of 1,011, 21%) sustained a structural knee injury. Accounting for potential confounders, having a structural knee injury was associated with more minutes per game played (odds ratio [OR] 1.1; 95% confidence interval [CI] 1.0-1.2; P = .002), a greater usage rate (OR 1.1; 95% CI 1.0-1.2; P = .004), and a lower player efficiency rating (OR 0.94; 95% CI 0.89-1.0; P = .041). A greater number of missed games was associated with more minutes per game (regression coefficient [RC] 0.065; 0.028-0.10; P = .001), fewer points per game (RC –0.078; –0.14 to –0.017; P = .013), and greater usage rate (RC 0.032; 0.0040-0.060; P = .025).

Conclusions

Structural knee injuries occurred in 21% of players in this study with an overall rate of 5.42 injuries per 1,000 game exposures. Significant risk factors associated with injury were minutes per game, usage rate, and true shooting percentage. Player efficiency was significantly associated with a decreased risk of injury. Increased minutes per game and usage rate were significantly associated with a longer duration of game loss.

Level of Evidence

Level IV, case series.

Prevalence of Cannabinoid (CBD) Use in Orthopaedic Sports Medicine Patients

Background:

Although there is some evidence that cannabinoid (CBD) products may provide a therapeutic effect for musculoskeletal pain, little is known about the usage patterns or their prevalence of use in orthopaedic sports medicine patients.

Purpose:

To report the prevalence and perceived self-efficacy of CBD products in patients evaluated in an orthopaedic sports medicine clinic.

Study Design:

Descriptive epidemiology study. Level of evidence, 2.

Methods:

The study population consisted of new patients who visited an orthopaedic surgery sports medicine clinic at a large academic center for consultation with a surgeon between August 2020 and March 2021. All patients were asked to complete a survey that assessed perceived pain and effectiveness of CBD products and other nonsurgical treatment modalities using the Single Assessment Numeric Evaluation score (range, 0-100) and the Numeric Pain Rating Scale (NRS). Descriptive factors were collected via chart review. Descriptive statistics were used to characterize the data.

Results:

Overall, 823 patients completed the survey (45.4% female; mean age, 51 years [range, 18-87 years]; mean body mass index, 28.9 [range, 17.2-58.4]). Body areas involved included 285 shoulders, 44 elbows, 76 hips, 276 knees, 58 ankles, and 77 other. Of these patients, 19% (152/823) endorsed the use of CBD products before their initial evaluation. The mean NRS for pain was significantly different between non-CBD users and CBD users (5.6 vs 6.1; P = .029). CBD users were significantly more likely to have tried other nonoperative modalities compared with nonusers, including nonsteroidal anti-inflammatory drugs (79.6% vs 69.8%; P = .032), bracing (44.7% vs 34.6%; P = .024), steroid injections (38.8% vs 21.6%; P < .001), and physical therapy (54% vs 36.1%; P < .001). In addition, 30.9% of CBD utilizers reported marijuana use compared with 2.8% of non-CBD users ( P < .001) for management of their pain.

Conclusion:

In the current study, 19% of patients had used CBD products to manage joint-related issues. Sports medicine providers should be aware of this high incidence of usage and the potential interactions CBD products may have with other treatment modalities. Further studies are needed to assess the effectiveness of CBD as a therapeutic agent and the specific interactions it has with other drugs and other forms of treatment.

Posterior Bony Impingement-Potential Mechanism of Ligamentum Teres Tears

PURPOSE

To describe a potential causal mechanism of ligamentum teres (LT) tears, a specific treatment for posterior impingement of the LT, and to report the minimum 2-year outcome of this treatment.

METHODS

We retrospectively reviewed data collected from 1,251 hip arthroscopies performed by the senior surgeon over a 26-month period. During this time, 424 LT tears were identified including 9 patients with isolated partial LT tears caused by impingement of the LT against a prominent acetabular fossa posterior wall and no other intra-articular pathology. All 9 patients were treated with LT tear debridement and excision of the impinging bony prominence using an arthroscopic burr. Patients were followed with a modified Harris hip score and nonarthritic hip score for a minimum of 24 months (mean, 29 months; range, 24-38 months).

RESULTS

After surgery, all patients returned to their preinjury level of activity. The modified Harris hip score increased from a mean of 58.9 preoperatively (range, 41.8-84.7) to 89.2 (range, 70.3.5-96.7) (P = .02) at a minimum of 2-year follow-up. Similarly, the nonarthritic hip score increased from a mean of 56.2 (range, 35-90) to 91.9 (range, 81.5-98.5) (P = .01) at a minimum of 2 years after surgery. There were no complications associated with the procedure and no revision surgeries performed over the 2-year follow-up.

CONCLUSIONS

LT tears may, very uncommonly, be caused by impingement of the mid-part of the ligament against a prominent posterior acetabular fossa edge. In this group of 9 cases, debridement of the torn ligament segment, in combination with resection of the impinging bone, was associated with marked symptomatic improvement and full return to activities for a minimum of 2 years.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Tibial tunnel placement accuracy during anterior cruciate ligament reconstruction: independent femoral versus transtibial femoral tunnel drilling techniques

PURPOSE

This study aimed to compare the accuracy of tibial tunnel placement using independent femoral (IF) versus transtibial (TT) techniques.

METHODS

Ten matched pairs of cadaveric knees were randomized so that one knee in the pair underwent arthroscopic TT drilling of the femoral tunnel and the other underwent IF drilling through an accessory medial portal. For both techniques, an attempt was made to place the femoral and tibial tunnels as close to the center of the respective anterior cruciate ligament (ACL) footprints as possible. Preoperative and postoperative computed tomography using a technique optimized for ligament evaluation allowed comparison of the anatomic ACL tibial footprint to the tibial tunnel aperture. The percentage of tunnel aperture contained within the native footprint, as well as the distance from the center of the tunnel aperture to the center of the footprint, was measured. Additionally, graft obliquity relative to the tibial plateau was evaluated in the sagittal plane.

RESULTS

The percentage of tibial tunnel aperture contained within the native footprint averaged 71.6% ± 17.2% versus 52.1% ± 23.4% (P = .04) in the IF and TT groups, respectively. The distance from the center of the footprint to the center of the tibial tunnel aperture was 3.50 ± 1.6 mm and 4.40 ± 1.7 mm (P = .27) in the IF and TT groups, respectively. TT drilling placed 6 of 10 tunnels posterior to the center of the footprint versus 3 of 10 tunnels in IF drilling. The graft obliquity angles were 54.8° in TT specimens and 47.5° in IF specimens (P = .09).

CONCLUSIONS

This study adds to the literature suggesting that TT drilling with an 8-mm reamer has deleterious effects on tibial tunnel aperture and position. IF drilling, which does not involve repeated reaming of the tibial tunnel, is associated with the placement of a higher percentage of the tunnel aperture within the native tibial footprint. There was not a significant difference between the IF and TT techniques in their ability to place the center of the tibial aperture near the center of the footprint or in graft obliquity.

CLINICAL RELEVANCE

ACL reconstruction has continued to evolve in an attempt to restore the functional anatomy and biomechanical behavior of the knee. Tibial tunnel characteristics-such as location, aperture topography, and tunnel obliquity-are important factors to consider in ACL reconstruction. This study compares tibial tunnels after IF and TT techniques.

The ligamentum teres test: a novel and effective test in diagnosing tears of the ligamentum teres

BACKGROUND

A ligamentum teres (LT) injury is a common finding at the time of hip arthroscopic surgery in patients with chronic groin and hip pain; however, LT tears have been difficult to identify before surgery. There have been no unique features identified on history assessment, physical examination, or imaging that reliably identify injuries of the LT preoperatively.

PURPOSE

To report a new clinical examination to assess the presence of an LT tear: the LT test.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

The study consisted of 75 patients undergoing hip arthroscopic surgery for multiple lesions. Each patient was evaluated by 2 independent examiners using the LT test, leading to a total of 150 tests being performed. The LT test is conducted with the hip flexed at 70° and 30° short of full abduction; the hip is then internally and externally rotated to its limits of motion. Pain on either internal or external rotation is consistent with a positive LT test result. Hip arthroscopic surgery was then performed and all intra-articular abnormalities noted. Arthroscopic images were taken of each LT and examined by a third independent examiner who determined the presence or absence of a tear. Clinical examination findings were compared with the arthroscopic findings to determine the sensitivity, specificity, and positive and negative predictive values. In addition, the presence of intra-articular pathological lesions was compared with the test results to determine if there was a correlation between the presence of an intra-articular pathological abnormality and a positive LT test result.

RESULTS

Of the 150 examinations performed, the test result was positive 55% of the time (77 examinations). The sensitivity and specificity of the test were 90% and 85%, respectively. The positive predictive value was 84%, and the negative predictive value was 91%. The presence of an LT tear, pincer lesion, and labral tear that required repair was associated with a positive LT test result. The κ coefficient for interobserver reliability was .80.

CONCLUSION

The LT test is an effective way of assessing the presence of LT tears with moderate to high interobserver reliability. In addition to an LT tear, the presence of a pincer lesion or labral tear requiring repair are also associated with a positive LT test result.

Case report: reconstruction of the distal tibia with porous tantalum spacer after resection for giant cell tumor

Treatment options for giant cell tumors of the distal tibia include curettage and cement packing, curettage and bone grafting, or resection and reconstruction for aggressive tumors. Curettage of aggressive tumors often leads to severe bone loss requiring reconstruction. Allograft and autograft may be effective options for reconstruction, but each is associated with drawbacks including the possibility of infection and collapse. We present a case of giant cell tumor of the distal tibia treated with curettage and arthrodesis using a porous tantalum spacer. Complete removal of the tumor and successful arthrodesis of the ankle were accomplished using the spacer. The patient returned to pain-free walking along with eradication of the giant cell tumor. We believe porous tantalum spacers are a reasonable option for reconstructing the distal tibia after curettage of a giant cell tumor with extensive bone loss.

Hand-mixed and premixed antibiotic-loaded bone cement have similar homogeneity

Since low-dose antibiotic-loaded bone cement (ALBC) was approved by the FDA for second-stage reimplantation after infected arthroplasties in 2003, commercially premixed low-dose ALBC has become available in the United States. However, surgeons continue to mix ALBC by hand. We presumed hand-mixed ALBC was not as homogeneous as commercially premixed ALBC. We assessed homogeneity by determining the variation in antibiotic elution by location in a batch, from premixed and hand-mixed formulations of low-dose ALBC. Four hand-mixed methodologies were used: (1) suspension--antibiotic powder in the liquid monomer; (2) no-mix--antibiotic powder added but not mixed with the polymer powder before adding monomer; (3) hand-stirred--antibiotic powder stirred into the polymer powder before the monomer was added; and (4) bowl-mix--antibiotic powder mixed into polymer powder using a commercial mixing bowl before the monomer was added. Antibiotic elution was measured using the Kirby-Bauer bioassay. None of the mixing methods had consistently dissimilar homogeneity of antibiotic distribution from the others. Based upon our data we conclude hand-mixed low-dose ALBC is not less homogeneous than commercially premixed formulations.