Isabella T. Wu

Incidence of symptomatic osteochondritis dissecans lesions of the knee: a population-based study in Olmsted County

OBJECTIVEnTo (1) define population-based incidence of knee Osteochondritis dissecans (OCD) lesions using the population of Olmsted County, (2) examine trends over time, and (3) evaluate rate of surgical management over time.nnnMETHODnStudy population included 302 individuals who were diagnosed with knee OCD lesions between January 1, 1976 and December 31, 2014. Complete medical records were reviewed to extract injury and treatment details. Age- and gender-specific incidence rates were calculated and adjusted to the 2010 US population. Poisson regression analyses were performed to examine incidence and surgery trends by age, gender, and calendar period.nnnRESULTSnOverall age- and gender-adjusted incidence annual incidence of knee OCD lesions was 6.09 per 100,000 person-years. The incidence was significantly higher (Pxa0<xa00.001) in males (8.82, 95% CI 7.63 to 10.00 per 100,000) compared to females (3.32, 95% CI 2.61 to 4.04 per 100,000). Age- and gender-specific incidence was highest in both males and females in the 11-15 years old at 39.06 and 16.15 per 100,000, respectively. In males aged 11-15 years, OCD incidence increased significantly over the study period from 20.68 in 1976-1985 to 48.16 in 2006-2014 (per 100,000).nnnCONCLUSIONSnOverall age- and gender-adjusted annual incidence of knee OCD lesions in the Olmsted Country Population was 6.09 per 100,000 person-years with a significantly higher incidence in males compared to females. The highest incidence for both males and females occurred between the ages 11-15 years. Trends indicate increasing OCD incidence in younger males and decreasing surgical management in females over the last decade.

High Rate of Missed Lateral Meniscus Posterior Root Tears on Preoperative Magnetic Resonance Imaging

Background: Lateral meniscus posterior root tears (LMPRTs), if left untreated, can cause devastating effects to the knee, with rapid articular cartilage degeneration and loss of the meniscus as a secondary stabilizer. Detection and surgical repair of these defects have been linked to favorable outcomes, but preoperative identification of LMPRTs continues to be challenging. Purpose: To determine the rate of LMPRTs diagnosed preoperatively on magnetic resonance imaging (MRI) in a consecutive series of arthroscopically confirmed LMPRTs. Study Design: Case series; Level of evidence, 4. Methods: A retrospective cohort of 45 consecutive patients with arthroscopically confirmed LMPRTs between 2010 and 2017 were included in this study. The preoperative MRI report for each patient was evaluated and compared with intraoperative findings. Each preoperative MRI study was then reviewed by 2 fellowship-trained musculoskeletal radiologists who worked in consensus. Results: A total of 45 patients (32 males, 13 females) with arthroscopically confirmed LMPRTs and a mean age of 27 years (range, 14-54 years) were included in the study. Only 15 of 45 LMPRTs (33%) were initially diagnosed on preoperative MRI. Past or concurrent anterior cruciate ligament (ACL) reconstruction was present in 37 of 45 cases (82%). Upon retrospective review, 15 of the 30 missed LMPRTs were “clearly evident,” 12 “subtly evident,” and 3 “occult” (unavoidably missed). There were no significant differences in the rate of LMPRT diagnosis based on history of prior knee surgery, meniscus extrusion, or tearing of the meniscofemoral ligament. Conclusion: Despite improved identification of other meniscus tear patterns on MRI, a high percentage of LMPRTs were still missed. In the setting of previous ACL reconstruction, if the root cannot be confidently identified, the MRI interpretation should indicate that “the root is poorly visualized” to alert the surgeon to thoroughly evaluate this structure. The surgeon should maintain a high index of suspicion and carefully probe the posterior root of the lateral meniscus at the time of arthroscopy, especially in cases of ACL injury.

A simple cinch is superior to a locking loop for meniscus root repair: a human biomechanical comparison of suture constructs in a transtibial pull-out model

PurposeTo determine the cyclic displacement and ultimate failure loads of two clinically relevant suture configurations for repair of medial and lateral meniscus root tears.MethodsA total of 10 matched pair fresh-frozen, human meniscus specimens were randomly assigned to either simple cinch or locking loop meniscus–suture fixation techniques for transtibial pull-out repair in either medial (nxa0=xa010 matched pairs) or lateral (nxa0=xa010 matched pairs) meniscal root tears. The menisci were subjected to cyclic tensioning at 10–30xa0N for 1000 cycles at 0.5xa0Hz, and then post-cycling load to failure was performed at a tensile rate of 0.5xa0mm/s.ResultsFor both the medial and lateral meniscus, there was significantly less displacement with the cinch stitch at 100, 500 and 1000 cycle counts (pxa0<xa00.05). In respect to ultimate load, there was no significant difference in type of repair between the two suture configurations. When comparing ultimate load to failure from the medial to the lateral side, the ultimate load to failure was significantly greater for both suture configurations in the lateral meniscus root repair (pxa0<xa00.05). However, there was no significant difference in cyclic displacement between the medial and lateral meniscus.ConclusionsThe cinch stitch was significantly better at resisting displacement compared to the locking loop stitch configuration, and had similar ultimate load to failure. The lateral meniscus root repair construct has higher failure loads compared to the medial meniscus, independent of suture configuration.

Is Treatment of Segond Fracture Necessary With Combined Anterior Cruciate Ligament Reconstruction? Response

Background: There is a paucity of clinical information to guide the treatment of a combined anterior cruciate ligament (ACL) tear and Segond fracture. Purpose: To compare clinical outcomes, graft failure rates, and activity levels between patients undergoing ACL reconstruction (ACLR) with and without an untreated Segond fracture at a minimum 2-year follow-up. Study Design: Cohort study; Level of evidence, 3. Methods: This study included a group of patients with a combined ACL tear/untreated Segond fracture that was matched based on age, sex, body mass index, and graft type to a control group of patients with an ACL tear and no Segond fracture. All patients were treated with ACLR alone between the years of 2000 and 2015. The diagnosis of a Segond fracture, or bony avulsion of the anterolateral complex, was made by radiographic analysis. Data regarding the initial injury, surgical intervention, and physical examination findings were recorded. Clinical and functional outcomes were obtained using physical examination results, International Knee Documentation Committee (IKDC) subjective scores, and Tegner activity levels. Results: Twenty patients (16 male, 4 female) with a combined ACL tear/untreated Segond fracture with a mean age of 26.3 years (range, 13-44 years) were matched to a control group of 40 patients (32 male, 8 female) with an ACL tear and no Segond fracture with a mean age of 26.4 years (range, 13-47 years). The study group was followed for a mean of 59.1 months (range, 24-180 months) and the control group for a mean of 55.5 months (range, 24-120 months). The mean IKDC score was 86.5 (range, 54-100) for the study group compared with 93.0 (range, 54-100) for the control group (P = .03). The graft rupture rate was 10% for both groups (P = .97). The mean time to rupture was 33.0 months (range, 21-45 months) in the study group and 63.5 months (range, 39-88 months) in the control group (P = .24). Patients in the study group had significantly more anteroposterior instability by preoperative Lachman testing than those in the control group (control group: 0 normal, 3 grade 1+, 37 grade 2+, 0 grade 3+; study group: 0 normal, 1 grade 1+, 10 grade 2+, 9 grade 3+; P = .0001). There was no significant difference between the 2 groups in regard to postoperative Lachman testing (control group: 35 normal, 3 grade 1+, 2 grade 2+, 0 grade 3+; study group: 17 normal, 3 grade 1+, 0 grade 2+, 0 grade 3+; P = .31). Patients in the study group had significantly more instability by preoperative pivot-shift testing than those in the control group (control group: 0 normal, 7 grade 1+, 33 grade 2+, 0 grade 3+; study group: 1 normal, 1 grade 1+, 11 grade 2+, 7 grade 3+; P = .0003). No significant difference was found between the 2 groups for postoperative pivot-shift testing (control group: 36 normal, 2 grade 1+, 2 grade 2+, 0 grade 3+; study group: 18 normal, 1 grade 1+, 1 grade 2+, 0 grade 3+; P = .61) or final Tegner activity level (median, 6). Conclusion: At midterm follow-up, patients undergoing ACLR with and without a Segond fracture had similar pivot-shift test results, graft failure rates, and activity levels. The IKDC score was statistically worse in the patients with a combined ACL tear/untreated Segond fracture, but the difference was less than the minimal clinically important difference for the IKDC score. These findings suggest that patients with a combined ACL tear/untreated Segond fracture can have comparable outcomes to patients with an ACL tear and no Segond fracture when treated with ACLR alone.

Successful Return to Sport Following Distal Femoral Varus Osteotomy

Objective Distal femoral varus osteotomy (DFVO) is an effective treatment for unloading valgus knee malalignment; however, there is limited evidence on the ability for patients to return to athletics following this procedure. The purpose of this study is to report the functional outcomes and rate of return to sport for athletes that underwent DFVO. Design A consecutive series of athletes that had undergone DFVO were retrospectively reviewed. Radiographs were assessed to determine preoperative and postoperative alignment. Institutional registries were used to collect preoperative and postoperative Marx Activity Scale, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form scores, and return to sport. Results Thirteen patients (8 males, 5 females) with a mean age of 24 years (range 17-35 years) and a mean follow-up of 43 months (range 24-74 months) were included in the study. Six patients underwent medial closing wedge DFVO versus 7 patients who underwent lateral opening wedge DFVO. Nine of 13 had concomitant chondral, meniscal, or ligamentous procedures performed. The mean alignment correction was 8° (range 5°-13°). All patients were able to successfully return to sport at a mean of 11 months (range 9-13 months). Furthermore, all 13 patients demonstrated an improvement in both Marx Activity Scale (4-11; P < 0.01) and IKDC scores (53-89; P < 0.01) after surgery. Conclusions Correction of valgus knee malalignment through DFVO—either medial closing wedge or lateral opening wedge—can reliably result in improvement in function and return to sport. Concomitant chondral, meniscal, and ligamentous pathology should be addressed.

Patellar Tendon Repair With Ipsilateral Semitendinosus Autograft Augmentation

Patellar tendon ruptures are rare but potentially devastating injuries. Acute repair after patellar tendon rupture affords the best opportunity for tension-free restoration of the extensor mechanism. Biological augmentation of primary repair is believed to decrease strain across the repair site and reduce the risk of rerupture. We present a technique for primary patellar tendon repair with bidirectional fixation using transosseous tunnels, suture anchor fixation, and ipsilateral hamstring autograft augmentation in a distal patellar pole socket.

Medial Closing-Wedge Distal Femoral Osteotomy with Medial Patellofemoral Ligament Imbrication for Genu Valgum with Lateral Patellar Instability

A varus-producing distal femoral osteotomy (DFO) is an effective technique for the treatment of lateral patellar instability (LPI) in patients with concomitant moderate to severe valgus malalignment. Patellar maltracking and subluxation are corrected via neutralization of some of the laterally directed forces on the patella due to the valgus deformity. This can be accomplished with a distal femoral lateral opening-wedge or medial closing-wedge osteotomy and medial soft tissue stabilization. A medial closing-wedge osteotomy offers the advantages of immediate weight bearing and a single incision in cases requiring patellofemoral soft tissue stabilization. In this article, we describe our preferred operative technique for a medial closing-wedge DFO using a femoral locking plate and medial patellofemoral ligament imbrication for the correction of LPI.

The Rapidly Assessed Predictor of Intraoperative Damage (RAPID) Score: An In-Clinic Predictive Model for High-Grade Acetabular Chondrolabral Disruption

Background: The preoperative assessment of cartilage lesions is critical to surgical planning and decision making. The accurate radiographic determination of acetabular cartilage damage has remained elusive for modern imaging modalities, including magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA). While risk factors have been individually described, no multivariable system exists for predicting high-grade cartilage damage. Purpose: To determine the preoperative predictors of grade 3 to 4 acetabular labrum articular disruption (ALAD) lesions. Study Design: Case-control study; Level of evidence, 3. Cohort study (diagnosis); Level of evidence, 1. Methods: Retrievable radiographs were reviewed from primary hip arthroscopic procedures performed at 2 high-volume institutions between December 2007 and April 2017. The predictive value of demographic and radiographic factors for the intraoperative documentation of ALAD grade 3 to 4 damage was analyzed and entered into a multivariable model, and a statistically guided scoring system for the damage risk was created using the Akaike information criterion. The scoring system was then prospectively validated on 167 patients who underwent primary hip arthroscopy between April 2017 and February 2018. Results: A total of 652 primary hip arthroscopic procedures in 614 patients (390 female, 224 male; mean age, 33.2 ± 12.5 years; mean body mass index, 26.9 ± 5.5 kg/m2) from 2007 to 2017 were analyzed. Male sex (odds ratio [OR], 3.11; P < .01), age ≥35 years (OR, 1.96; P < .01), cam morphology (alpha angle >55°) (OR, 2.96; P < .01), and Tönnis grade 1 to 2 (grade 1: OR, 4.14; P < .01, and grade 2: OR, 9.29; P < .01) were univariate risk factors for intraoperatively documented high-grade damage. A multivariable scoring system, the Rapidly Assessed Predictor of Intraoperative Damage (RAPID) score (0-5 points), was generated based on sex, Tönnis grade, and cam morphology. Patients with increasing RAPID scores had an increasing risk of damage, with a 10.5% risk for those with 0 points and an 88.0% risk for those with 5 points (P < .01). The area under the curve was 0.75 for the study group and 0.76 for the validation group (P = .94). Conclusion: While preoperative MRI has diagnostic value for hip arthroscopic surgery, the RAPID score provides added benefit as a readily employable, in-clinic system for predicting high-grade cartilage damage. The discriminatory value of the RAPID score compares favorably with previous MRI and MRA studies. This information will help the clinician and patient plan for high-grade damage and identify potential targets for cartilage treatment.

Individualizing the tibial tubercle to trochlear groove distance to patient specific anatomy improves sensitivity for recurrent instability.

PurposeAn initial episode of patellar instability poses a treatment challenge given the absence of a valid, reproducible, and universally applicable predictor of recurrence. Recently, a series of patellar instability ratios (PIRs) were described. Each ratio consisted of the traditional tibial tubercle to trochlear groove (TT-TG) distance normalized to patient-specific measures. The purpose of this study was to investigate the reliability and validity of these novel measures.MethodsEighty-seven patients experiencing a first-time lateral patellar dislocation were identified in a retrospective manner. Magnetic resonance imaging (MRI) studies obtained at the time of injury were reviewed. The TT-TG distance, patellar width (PW), trochlear width (TW), patellar length (PL), and trochlear length (TL) were obtained by two observers in a blinded, randomized fashion. Measurement reliability was assessed using intra-class correlation coefficients (ICCs). Patients were divided into those having a single dislocation (Group 1) and those experiencing recurrent instability (Group 2). The ability of the TT-TG distance and each PIR to predict recurrent instability was assessed by calculating odds ratios (ORs) with 95% confidence intervals (CIs). Sensitivity and specificity were also calculated for each measure.ResultsExcellent inter-rater agreement was observed with ICCsu2009>u20090.75 for all patellofemoral joint measurements obtained on MRI. The TT-TG distance alone was predictive of recurrent patellar instability with an OR of 8.9 (pu2009<u20090.001). However, the isolated TT-TG distance had the lowest sensitivity at 25.6%. Among ratios, a TT-TG/PLu2009≥u20090.5 was the most predictive of recurrent instability with an ORs of 6.1 (pu2009=u2009<u20090.001). A TT-TG/TLu2009≥u20090.8 was also predictive of recurrence (OR 4.9, pu2009=u20090.027) and had the highest sensitivity of any measure at 94.9%.ConclusionThe results of the current study support the reproducibility and predictive ability of PIRs. While a TT-TGu2009≥u200920xa0mm was the strongest predictor of recurrent patellar instability, it was a relatively insensitive measure. Sensitivity may be improved by normalizing the TT-TG distance to patient-specific axial and sagittal plane patellofemoral measurements on MRI. Ultimately, PIRs are reproducible measures that may serve as an additional tool when clinically assessing the unstable patellofemoral joint.Level of evidenceIII.

Posterolateral Corner Reconstruction using the Anatomical Two-Tailed Graft Technique: Clinical Outcomes in the Multiligament Injured Knee

&NA; Injury to the posterolateral corner (PLC) of the knee can lead to both varus and rotational instability. Multiple PLC reconstruction techniques have been described, including one‐tailed graft (fibula‐based constructs) or two‐tailed graft (combined fibula‐ and tibia‐based constructs). The purpose of our study was to evaluate the clinical outcomes of anatomical two‐tailed graft reconstruction of the PLC in the setting of multiligament knee injuries (MKLIs) with grade III varus instability. Patients were identified through a prospective MLKI database between 2004 and 2013. Patients who received fibular collateral ligament and PLC reconstructions using a two‐tailed graft and had a minimum follow‐up of 2 years were included. Patients were assessed for clinical laxity grade, range of motion, and functional outcomes using Lysholm and International Knee Documentation Committee (IKDC) scores. Twenty patients (16 male, 4 female) with a mean age of 30.7 (range: 16‐52) and a mean follow‐up of 52.2 months (range: 24‐93 months) were included. Knee dislocation (KD) grades included: 4 KD‐1, 10 KD 3‐L, 5 KD‐4, and 1 KD‐5. No patients had isolated PLC injuries. Mean IKDC and Lysholm score were 73.1 ± 25.8 and 78 ± 26, respectively. Mean range of motion was ‐1.1 to 122.8. In full extension, two patients (10%) had grade 1 laxity to varus stress. In 30 degrees of knee flexion, five (25%) patients had grade 1 laxity, and two (10%) had grade 2 laxity. Anatomical two‐tailed PLC reconstruction can reliably restore varus stability when performed on patients with MLKIs and type C posterolateral instability with hyperextension external rotation recurvatum deformity. Satisfactory functional outcome scores were achieved in the majority of patients. This study supports the use of an anatomical two‐tailed PLC reconstruction in the multiligament injured knee. The level of evidence is IV, case series.