Improvement of Coracoid Process Union Rates: A Comparative Study of Conventional Open and Arthroscopic-assisted Bristow Procedures for Treating Anterior Shoulder Instability in Rugby Players.

BACKGROUND: The Bristow coracoid transfer procedure is a reliable technique for treating anterior shoulder instability in patients with large glenoid bone loss or those involved in collision sports. However, its success is marred by its inferior bone union rate of the coracoid process as compared to the Latarjet procedure. This study aimed to evaluate whether arthroscopic confirmation of the secured coracoid fixation during the Bristow procedure improves the bone union rate and clinical outcomes as compared to the open procedure. METHODS: We retrospectively reviewed 104 rugby players (n = 111 shoulders) who underwent an open (n = 66 shoulders) or arthroscopy-assisted (AS-assisted; n = 45 shoulders) Bristow procedure at our center from 2007 to April 2019. In the AS-assisted group, the screw fixation and coracoid stability and contact were confirmed under arthroscopic visualization. Graft union was evaluated through computed tomography at 3 months, 6 months, and 1 year postoperatively. Patient-reported outcome measures were assessed based on the American Shoulder and Elbow Surgeons (ASES) score, Rowe score, and satisfaction rate. Recurrence, the rate of return to play (RTP), and the frequency of pain after RTP were also assessed. RESULTS: The mean follow-up period was 73.5 (range: 45-160) months for the open group and 32.3 (range: 24-56) months for the AS-assisted group. In the former, the rates of bone union were 50%, 72.7%, and 88.9% at 3 months, 6 months, and 1 year, respectively. In contrast, the AS-assisted group had significantly greater bone union rates-88.9%, 93.3%, and 95.6% at 3 months, 6 months, and 1 year, respectively. Both groups showed significant improvement in the ASES and Rowe scores compared to preoperative values as well as high satisfaction rates (open: 92%; AS-assisted: 95.7%). There were no statistically significant differences in the recurrence and RTP rates as well as the frequency of pain after RTP between the two groups. CONCLUSION: The AS-assisted procedure allows early and high bone healing without compromising the clinical outcomes.

Ultrasonic Technique for Femoral Tunnel Creation in Anterior Cruciate Ligament Reconstruction.

Bone tunnel creation in the anatomical location is essential in anterior cruciate ligament (ACL) reconstruction with an autogenous graft and is commonly performed with a drill bit matched to graft diameter. Anatomic rectangular tunnel ACL reconstruction with a bone-patellar tendon-bone autograft has been developed to anatomically create bone tunnels inside the ACL footprints and has been reported to achieve excellent outcomes. To make the rectangular tunnel, the surgeon needs to dilate 2 adjacent bone tunnels after creation of 2 round tunnels with a drill bit, while the tunnel wall occasionally cracks during dilating. An ultrasonic (US) device was developed with improvement of output power and has been implemented with a rectangular shape blade in the field of arthroscopic surgery. This US device can provide a precise and effective bone cut compared to drills. We introduced this device to clinically create a rectangular tunnel during ACL reconstruction. The US device can be useful for rectangular femoral tunnel creation and can create a precise rectangular femoral tunnel in the ACL footprint.

Association Between Preoperative Glenoid Bone Loss and Postoperative Outcomes After Coracoid Transfer Combined With Open Bankart Repair: Comparison of the Bristow and Latarjet Techniques.

Background: Whether the extent of glenoid bone loss (GBL) affects clinical outcome after coracoid process transfer (CPT) is still unclear. Purpose: To evaluate postoperative outcomes after CPT combined with open Bankart repair in young rugby players in terms of the extent of GBL and between the Bristow and Latarjet techniques. Study Design: Cohort study; Level of evidence, 3. Methods: The authors investigated 101 shoulders in 91 competitive rugby players who underwent CPT combined with open Bankart repair by the Bristow (group B; 66 shoulders) or Latarjet (group L; 35 shoulders) procedure between 2007 and 2017. The extent of GBL was calculated from the en face view of the glenoid on preoperative 3-dimensional computed tomography scans and was used to categorize shoulders into 4 grades (grade 0, 0%; grade 1, >0% and ≤10%; grade 2, >10% and ≤20%; grade 3, >20%). At the minimum 2-year follow-up, the authors analyzed the relationship between GBL or GBL grade and postoperative outcome scores (American Shoulder and Elbow Surgeons score, Rowe score, Western Ontario Shoulder Instability Index, and patient satisfaction), return-to-play (RTP) times, graft failure (insufficient union or translocation), and recurrence. Results: The mean GBL in all shoulders was 10.9% ± 9.2% and was not significantly different between the 2 groups. There were no significant correlations between GBL and any outcome measure in either group. The mean RTP time was significantly shorter in group L versus group B (4.8 ± 1.1 vs 5.8 ± 1.8 months, respectively; P = .002), but it was not associated with GBL. In group B, the rate of graft failure was not significantly higher in shoulders with grade 0 or 1 GBL versus grade 2 or 3 GBL (8 [25.0%] vs 4 [11.8%], respectively; P = .21). In group B, graft failure was confirmed in 12 shoulders (18.2%), compared with 1 shoulder (2.9%) in group L. Postoperative recurrence occurred in significantly fewer shoulders in group B than in group L (2 [3.0%] vs 5 [14.3%], respectively; P = .047). Conclusion: The extent of GBL did not affect outcome scores after CPT, regardless of operative procedure.

Glenoid defect size increases but the bone fragment rarely resorbs in shoulders with recurrent anterior instability.

Background: With recurrent anterior instability the bone fragment of a bony Bankart lesion is often small compared to the glenoid defect. The purpose of the present study was to clarify the changes to both the bone fragment and glenoid defect over time in a single subject. Methods: Participants were patients who underwent computed tomography (CT) at least twice after an instability event between 2004 and 2021 and had a fragment-type glenoid at first CT. The glenoid rim width (A), glenoid defect width (B), and bone fragment width (C) were measured in millimeters. If B or C increased by 1 mm or more from the first to final CT, the change was judged as "enlarged," and if B or C decreased by 1 mm or more, it was judged as "reduced"; all other cases were judged as "similar." Then, glenoid defect size and bone fragment size were calculated as B/A×100% and C/A×100%, respectively, and the changes from the first to final CT were compared. Results: From the first to final CT, the glenoid defect was enlarged in 30 shoulders, similar in 13 shoulders, and reduced in 4 shoulders, and the bone fragment was enlarged in 18 shoulders, similar in 24 shoulders, and reduced in 5 shoulders. The mean glenoid defect size significantly increased from 10.9% to 15.3% (P < .001), and the mean bone fragment size increased from 6.4% to 7.8%, respectively (P = .005). At the final CT, in 6 shoulders a new glenoid fracture was observed at a different site from the original fracture. When they were excluded from the analyses, the mean glenoid defect size still significantly increased (from 11.2% to 15.2%; P < .001), but the mean bone fragment size did not (6.5% vs. 7.3%, respectively; P = .088). Conclusions: In shoulders with recurrent anterior instability, glenoid defect size appears to increase significantly over time, whereas the bone fragment size remains unchanged or increases only slightly. Bone fragment resorption is quite rare, and a bone fragment appears to be small because of an enlarged glenoid defect.

Anterior glenoid rim erosion in the early stage after arthroscopic Bankart repair affects postoperative recurrence.

Background: Recent studies reported that anterior glenoid rim erosion can occur in the early period after arthroscopic Bankart repair (ABR) for traumatic anterior shoulder instability. However, it is unknown whether such erosion is a risk factor for postoperative recurrence. This study evaluated risk factors for postoperative recurrence after ABR, specifically aiming to elucidate whether reduction of postoperative glenoid width due to anterior glenoid rim erosion is one of such factors. Methods: A total of 220 shoulders that underwent ABR alone between 2013 and 2020 were retrospectively investigated. Patient age at surgery, whether the patient was a collision/contact athlete, anchor placement, preoperative glenoid bone defect (%), localization of the Hill-Sachs lesion, and change of glenoid width (%) in the 6 months after surgery were investigated for their statistical relation to recurrence by univariate and multiple logistic regression analysis. Results: Postoperative recurrence occurred in 32 of 220 shoulders (14.5%). In univariate analysis, being a collision/contact athlete was the only variable with a significant effect on recurrence (odds ratio [OR], 2.555; 95% confidence interval [CI], 1.123-5.814; P = .03). Change of glenoid width reduction was larger in those with recurrence than without recurrence, but the difference was not statistically significant (-7.0 ± 6.6% vs. -5.0 ± 9.3%; P = .14). However, in multivariate logistic analysis, preoperative glenoid bone defect (%) (adjusted unit OR, 1.076; 95% CI, 1.018-1.137; P = .010) and postoperative change of glenoid width (%) (adjusted unit OR, 0.946; 95% CI, 0.900-0.994; P = .028) had a significant influence on postoperative recurrence. Conclusion: Glenoid width reduction due to anterior glenoid rim erosion after ABR is a risk factor for recurrence.

Is preoperative glenoid defect size a reliable indicator of postoperative recurrence after arthroscopic Bankart repair in teenage competitive athletes?

BACKGROUND: Being younger than 20 years of age at the time of arthroscopic Bankart repair (ABR) is known to be one of the most important risk factors for postoperative recurrence of instability. When deciding on the appropriate surgical approach, surgeons generally consider only the size of a critical glenoid defect, and most of them do not take into account factors such as the size of bone fragments and possible bone union after arthroscopic bony Bankart repair (ABBR). Therefore, this retrospective study aimed to clarify the risk factors for postoperative recurrence after ABR in teenage competitive athletes by focusing on glenoid rim morphologies and bone union. METHODS: Participants were 115 teenage competitive athletes without a capsular injury who underwent primary ABR for chronic traumatic anterior instability and were followed up for a minimum of 2 years. Possible risk factors for postoperative recurrence were investigated by univariate and multivariate analysis. In shoulders with a glenoid defect and bone fragment, the influence of glenoid defect size and bone fragment size on bone union after ABBR was also investigated. RESULTS: Postoperative recurrence was seen in 16 patients (13.9%). Regarding glenoid defect size, recurrence was seen in 1 (3.2%) of 31 shoulders with a glenoid defect smaller than 5% (including those with a normal glenoid), 15 (22.1%) of 68 shoulders with a glenoid defect of 5%-20%, and 0 (0%) of 16 shoulders with a glenoid defect of 20% or larger (P = .009). Regarding bone union, recurrence was seen in 4 (6.9%) of 58 shoulders with complete or partial bone union after ABBR and 8 (40%) of 20 shoulders with nonunion or disappearance of the bone fragment (P = .001). Regarding bone fragment size, recurrence was seen in 12 (20.7%) of 58 shoulders with a small or no bone fragment (<7.5%) and in 3 (8.6%) of 35 shoulders with a large bone fragment (≥7.5%; P = .154). Multivariate analysis identified non-union or disappearance of the bone fragment after ABBR as a significant risk factor for recurrence. Complete or partial bone union was seen in 25 (58.1%) of 43 shoulders with a small bone fragment (<7.5%) and 33 (94.3%) of 35 shoulders with a large bone fragment (≥7.5%; P < .001). CONCLUSIONS: In teenage competitive athletes, bone union after ABBR affects postoperative recurrence after ABR, regardless of the preoperative glenoid defect size, and bone union rate after ABBR is significantly influenced by bone fragment size.

New bone formation after arthroscopic Bankart repair for unstable shoulders with an erosion-type glenoid defect.

BACKGROUND: The purpose of the present study was to retrospectively evaluate new bone formation after arthroscopic Bankart repair (ABR) and the influence of new bone formation on recurrence in shoulders with an erosion-type glenoid defect. METHODS: We analyzed data on shoulders with an erosion-type glenoid defect. Participants were patients who underwent computed tomography to evaluate new bone formation after ABR performed from 2004 to 2021 and were followed for a minimum of 2 years. We investigated the factors influencing new bone formation, in particular the presence of an intraoperative bone fragment, and the influence of new bone formation and its size on postoperative recurrence. RESULTS: A total of 100 shoulders were included. The mean glenoid defect size was 10.1% ± 6.3% (range, 1.2%-31.5%). New bone formed postoperatively in 15 shoulders (15.0%) and was seen in significantly more shoulders with an intraoperative bone fragment (11 of 18, 61.1%) than in those without a fragment (4 of 82, 4.9%; P < .001). Recurrence occurred in 22 shoulders (22.0%), and the rate of recurrence was not different between shoulders with new bone formation (3 of 15, 20.0%) and without new bone formation (19 of 85, 22.4%; P = .999). Among the 15 shoulders with new bone formation, the size of the new bone fragments relative to glenoid width was <5% in 2 shoulders, 5%-<7.5% in 8 shoulders, 7.5%-<10% in 3 shoulders, and ≥10% in 2 shoulders; in all 3 shoulders with postoperative recurrence, the relative size was <7.5%. CONCLUSIONS: Even in shoulders with an erosion-type glenoid defect, new bone may form after ABR, especially in shoulders with an intraoperative bone fragment. However, new bone formation does not decrease the rate of postoperative recurrence.

Knot location in arthroscopic inside-out meniscal repair: Cadaveric evaluation.

BACKGROUND: The inside-out repair technique is the gold standard for treatment of meniscal tears, while some soft tissues can be hung as the sutures are tied outside the capsule. The purpose was to clarify the association between the suture site and knot location in the arthroscopic inside-out technique. METHODS: Inside-out meniscal suture was arthroscopically performed on medial and lateral menisci in twenty-three cadaveric knees, on the assumption that longitudinal tear existed. A retractor was inserted above the semi-membranous tendon and anterior to the gastrocnemius for the medial side, while the retractor was placed in the anterior space of the gastrocnemius for the lateral side. After identifying three segments (anterior, middle and posterior segments), eight sutures were inserted into the following eight areas in each knee: anterior (M1, L1) and posterior (M2, L2) areas of the middle segment, and anterior (M3, L3) and posterior (M4, L4) areas of the posterior segment. Twelve knees underwent meniscal repair on femoral side and eleven passed sutures on the tibial side, while knots were tied outside of the joint. Attentive dissection was performed to assess the relation between knot locations and the principal structures around the knee joint. RESULTS: In medial meniscal suture, most sutures for the middle portion (M1, 2) bound medial collateral ligament (MCL), while a few cases included the semi-membranous tendon for the M4 area. In lateral meniscal suture, sutures for the L1 area tied some fibers of lateral collateral ligament (LCL) in high frequency, while popliteal muscles/tendons were tied over at the L3 area. CONCLUSIONS: Most suture knots were located on MCL or capsule in medial meniscus suture, while more than half sutures passed through LCL or popliteal tendon/muscle in lateral meniscus suture. An assistant should retract LCL under direct observation and the surgeon must confirm the direction of needle for lateral meniscal repair.

Unrecognized glenoid fracture in opposite shoulders with symptomatic anterior instability.

BACKGROUND: The purpose of the present study was to investigate the characteristics of unrecognized glenoid fracture in opposite shoulders with symptomatic anterior instability. METHODS: Participants were 38 patients, who had complaints of instability on only one side (symptomatic shoulder) and had no complaints despite of a glenoid fracture on the other shoulder (asymptomatic shoulder) from 2011 to 2020. Factors that could influence the onset of symptoms including glenoid rim morphology were retrospectively investigated. RESULTS: Among the asymptomatic shoulders, 16 had a single traumatic event and 22 had no history of trauma. The glenoid morphology was normal in 6, erosion in 12 and bony Bankart in 20 on the symptomatic side, whereas the respective shoulders were 0, 16 and 22 on the asymptomatic side. Bone union of bony Bankart was complete in 9, partial in 3 and non-union in 8 on the symptomatic side, whereas the respective shoulders were 18, 3 and 1 on the asymptomatic side. The mean glenoid defect size was 10.4% and 7.8%, and the mean bone fragment size was 5.0% and 4.5%, respectively. The mean medial displacement of bone fragments was 2.6 mm and 1.0 mm, respectively (p < 0.001). A larger glenoid defect (≥10%) was recognized in 19 symptomatic shoulders and 10 asymptomatic shoulders. Among them, erosion was solely recognized in 5 symptomatic shoulders. In shoulders with bony Bankart, all 10 asymptomatic shoulders had a completely or partially united fragment with less than 2 mm displacement. On the other hand, among 14 symptomatic shoulders, united fragment was solely recognized in 8 shoulders, in which medial displacement was less than 2 mm in 3 shoulders. CONCLUSIONS: Even if a glenoid fracture occurred, symptom such as instability or pain was not always recognized by all patients. Regardless of glenoid defect size, shoulders with a completely or partially united bone fragment and with less than 2 mm displacement were found to be asymptomatic.

The process of bone union after arthroscopic bony Bankart repair in younger athletes with a subcritical glenoid defect: An advantage of remained large bone fragment.

BACKGROUND: The purpose of the present study was to investigate the bone union process after arthroscopic bony Bankart repair (ABBR) in shoulders with a subcritical glenoid defect of 13.5% or larger. METHODS: Bone union process after ABBR performed from 2011 to 2018 were retrospectively investigated in 47 athletes younger than 30 years with a subcritical glenoid defect, who underwent CT at least twice postoperatively. The change of bone union between first CT within 6 months and final CT later than 6 months was investigated, especially noticing bone fragment size (≥7.5% versus <7.5%). RESULTS: The mean period at first CT and at final CT was 4.1 ± 0.6 months (3-6 months) and 16.8 ± 11.6 months (7-71 months), respectively. From the first to final CT, among 15 shoulders with a small bone fragment (<7.5%), complete union increased from 4 shoulders (26.7%) to 8 shoulders (53.3%), while among 32 shoulders with a large bone fragment (≥7.5%), complete union increased from 15 shoulders (46.9%) to 25 shoulders (78.1%). On the other hand, while non-union or disappeared bone fragment was recognized in 8 shoulders (53.3%) with a small fragment and in 2 shoulders (6.3%) with a large fragment at first CT, it was solely recognized in 4 shoulders (26.7%) with a small fragment and in no shoulders with a large fragment at final CT. While postoperative glenoid fracture at the site of bone union was recognized in 7 shoulders, complete union was finally obtained after conservative treatment in 5 shoulders. So, final complete union was obtained in 9 (60%) of 15 shoulders with a small fragment and in 29 (90.6%) of 32 shoulders with a large fragment (p = 0.021). CONCLUSIONS: In shoulders with a subcritical glenoid defect, when a large bone fragment (≥7.5%) was repaired, complete union rate was higher and complete union could be obtained earlier.

Open Bristow Versus Open Latarjet for Anterior Shoulder Instability in Rugby Players: Radiological and Clinical Outcomes.

Background: Coracoid transfer is a reliable method for managing anterior shoulder instability in athletes who play contact sports; however, differences between the Bristow and Latarjet procedures are unclear. Purpose: To compare clinical outcomes and rates of bone union and bone resorption of the coracoid process between the open Bristow and open Latarjet procedures in rugby players. Study Design: Cohort study; Level of evidence, 3. Methods: Rugby players who underwent an open Bristow or an open Latarjet procedure were retrospectively reviewed for anterior shoulder instability, and 66 shoulders in the Bristow group and 35 in the Latarjet group were included. Graft union and resorption were evaluated using computed tomography at 3 months to 1 year postoperatively. Patient-reported outcome measures (American Shoulder and Elbow Surgeons score, Rowe score, and satisfaction rate) were obtained at a mean follow-up of 74 months (range, 45-160 months) for Bristow and 64 months (range, 50-76 months) for Latarjet procedures. Recurrence and the rate of return to play (RTP), frequency of pain after RTP, and retirement rate after RTP were also assessed. Results: In 97.1% of the Latarjet procedure cases, bone union of the coracoid was achieved at 3 months postoperatively; however, bone union was achieved in only 72.7% of the Bristow procedure cases at 6 months postoperatively. Bone resorption of the coracoid process occurred in 6.1% of shoulders after the Bristow procedure, whereas 100% of shoulders showed bone resorption after the Latarjet procedure. No statistical differences were found in outcome scores between the 2 procedures. Subluxation and persistent pain after returning to sports were identified at a significantly higher rate in the Latarjet group (5 shoulders [14%] and 9 shoulders [26%], respectively) than in the Bristow group (2 shoulders [3%] and 2 shoulders [3%]) (P = .0471 and P = .001, respectively). Conclusion: The Latarjet procedure had an advantage in the early and high rate of bone union but was at a disadvantage in bone resorption compared with the Bristow procedure. Subluxation and pain after returning to sports were more frequent in patients who underwent the open Latarjet procedure than in those who underwent the open Bristow procedure.

Meniscal Displacement and Loss of Load-Transmission Function After Radial Tear of the Lateral Meniscus in a Porcine Model: New Insights Into the Functional Dynamics of the Injured Meniscus.

BACKGROUND: Meniscal extrusion/translation has been used as an index for meniscal treatment. However, the relationship between meniscal displacement and the degree of meniscal tear or load-transmission function of the lateral meniscus (LM) remains unclear. PURPOSE: To clarify the relationship between the width of the radial tear of the LM and (1) meniscal displacement or (2) resultant force through the meniscus under axial compressive load in the porcine model. STUDY DESIGN: Controlled laboratory study. METHODS: Eight intact porcine knees with or without a partial radial tear at the midbody of the LM (involving 30%, 60%, or 90% of its width) were investigated. Reflective markers were attached to the outer wall of the anterior, anteromiddle, posteromiddle, and posterior segments of the LM. A 300-N axial load was applied at 2 flexion angles (30° and 60°), and the 3-dimensional forces and trajectories of the knees were recorded. Marker movements were simultaneously tracked using a motion capture camera system. After total meniscectomy of the LM, the recorded knee trajectories were reproduced, and the resultant force through the LM was calculated (a force carried only by the meniscus in response to a load applied to the whole knee joint). RESULTS: At both flexion angles, the change in distance (mean ± SD) between the anterior and posterior markers under load increased significantly more in the anteroposterior direction in LMs with a 90% tear than in intact LMs (30°, 0.4 ± 0.3 vs 1.4 ± 0.8 mm, P = .004; 60°, 0.1 ± 0.7 vs 1.4 ± 1.0 mm, P < .001 [intact vs 90% tear]). The change in distance between the anteromiddle and posteromiddle markers at 30° also significantly increased in LMs with a 90% tear (0.2 ± 0.2 vs 1.3 ± 1.2 mm, P = .02 [intact vs 90% tear]). The resultant force was significantly lower in LMs with a 90% tear than in intact LMs (30°, 125 ± 47 vs 48 ± 20 N, P < .001; 60°, 93 ± 46 vs 43 ± 11 N, P = .002 [intact vs 90% tear]). We found no significant differences in either meniscal displacements or resultant forces between intact LMs and those with 30% or 60% tears. CONCLUSION: LMs with a 90%-width midbody radial tear lost load-transmission function with their displacement relative to the tibia primarily in the anteroposterior direction in the porcine model. CLINICAL RELEVANCE: Even 1 mm of displacement after meniscal injury is evidence that the load-transmission function of the meniscus is greatly impaired. When a displaced torn LM is diagnosed in preoperative imaging, meniscal repair surgery should be considered.

Remaining Large Bone Fragment of a Bony Bankart Lesion in Shoulders With a Subcritical Glenoid Defect: Association With Recurrent Anterior Instability.

BACKGROUND: A preoperative glenoid defect of 13.5% or larger is recognized as a subcritical glenoid defect at arthroscopic Bankart repair (ABR) for collision/contact athletes or military personnel. PURPOSE: To clarify the prevalence and size of remaining bone fragments in shoulders with a subcritical glenoid defect at recurrent anterior instability and to investigate the influence on postoperative recurrence after ABR for younger competitive athletes. STUDY DESIGN: Cohort study; Level of evidence, 4. METHODS: The study included 96 shoulders with recurrent instability that underwent ABR between July 2011 and March 2018 for shoulders with a subcritical glenoid defect. The patients were divided into 2 groups according to the glenoid defect size (13.5%-<20%, medium; ≥20%, large). The bone fragment size in each defect group was retrospectively investigated and classified into 4 groups (no, 0%; small, >0%-<5%; medium, 5%-<10%; large, ≥10%). The postoperative recurrence rate for each combination of glenoid defect size and bone fragment size was investigated for competitive athletes aged <30 years. The fragments, when present, were repaired to the glenoid. RESULTS: The glenoid defect size was 13.5%-<20% in 60 shoulders (medium defect group) and ≥20% in 36 shoulders (large defect group). The mean bone fragment size was 6.7% ± 5.1% and 8.9% ± 4.9%, respectively (P = .042). In the medium defect group, there were 15 shoulders (25%) without a bone fragment, 6 shoulders (10%) with a small fragment, 23 shoulders (38.3%) with a medium fragment, and 16 shoulders (26.7%) with a large fragment. In the large defect group, the respective numbers were 2 shoulders (5.6%), 6 shoulders (16.7%), 14 shoulders (38.9%), and 14 shoulders (38.9%). A medium or large bone fragment was more common in the large defect group (P = .252). Among 64 younger competitive athletes who underwent ABR with a minimum of 2 years of follow-up, postoperative recurrence was recognized in 7 of 38 (18.4%) athletes in the medium defect group, but it was not recognized in any of the 26 athletes in the large defect group (P = .036). Postoperative recurrence was recognized in 4 of 12 (33.3%) athletes with a small fragment or no fragment and in 3 of 52 (5.8%) athletes with a medium or large fragment (P = .019). CONCLUSION: A larger bone fragment frequently remained in shoulders with a subcritical glenoid defect at recurrent instability. The postoperative recurrence rate after ABR for younger competitive athletes was low when a remaining larger bone fragment was repaired.

The lateral meniscal extrusion after repair with concomitant anterior cruciate ligament reconstruction at a mean follow-up of 3.5 years.

BACKGROUND: A meniscal repair is often performed on radial/flap or longitudinal tears of the lateral meniscus (LM) combined with anterior cruciate ligament reconstruction (ACLR). However, it is unknown if meniscal extrusion changes over time after repair. This study evaluated whether meniscal extrusion of the LM is maintained after repair or progresses with time using magnetic resonance imaging (MRI). METHODS: Among 574 patients who underwent primary anatomic ACLR, 123 patients followed up for more than 2 years were retrospectively analyzed. Forty patients with concomitant radial/flap tears of the LM (group R), 43 with longitudinal LM tears (group L), and 40 with intact LM (group C, matched-control group) were included. Clinical findings (pain, range of motion, swelling, and anterior laxity), lateral joint space on radiograph, and meniscal extrusion on MRI were assessed. Lateral/posterior meniscal extrusions were examined preoperatively, within 3 weeks after surgery, and at the final follow-up, and the absolute values and relative values (the preoperative values as baseline) were assessed respectively. RESULTS: There were no significant differences in the clinical and roentgenographic findings among the groups. No difference was observed in the relative values within 3 weeks after surgery among three groups, although the absolute values were larger in the repaired groups than in group C. At the final follow-up, however, the lateral extrusion in group L had progressed significantly, compared with that in group C (P = 0.033), while no significant difference was detected in the lateral extrusion between groups R and C (P = 0.177). The posterior extrusion in groups R and L had progressed significantly compared with that in group C (P < 0.001). CONCLUSIONS: LM extrusion could not be improved even immediately after meniscal repair, and it progressed laterally and posteriorly for more than 2 years after surgery.

On-the-Edge Anchor Placement May Be Protective Against Glenoid Rim Erosion After Arthroscopic Bankart Repair Compared to On-the-Face Anchor Placement.

PURPOSE: This retrospective study aimed to compare the effects of 2 different anchoring placements on glenoid rim erosion after arthroscopic Bankart repair (ABR). METHODS: Shoulders that underwent ABR from January 2013 to July 2020 were divided into 2 groups according to anchor placement (on-the-face, group F; on-the-edge, group E). We retrospectively calculated the percent change of glenoid width (Δ) on the first postoperative computed tomography scan (CT; performed within 6 months) and second postoperative CT (performed at 6 to 12 months) relative to the width on the preoperative CT and compared percent changes between the 2 groups. Also, we investigated the influence of preoperative glenoid structures (normal, erosion, bony Bankart) and the postoperative recurrence rate. RESULTS: We examined 225 shoulders in 214 patients (group F, n = 151; group E, n = 74). At first CT, anchoring placement was significantly associated with postoperative decrease of glenoid width (group F, -7.6% ± 7.9%; group E, -0.1% ± 9.7%; P < .0001). The difference between groups F and E was significant in shoulders with a preoperative glenoid defect (bony Bankart, -6.6% ± 8.8% vs 2.5% ± 11.2%, respectively; P < .0001; erosion, -6.6% ± 6.2% vs -2.6% ± 5.3%, respectively; P = .03). In 112 shoulders, CT was performed twice; Δ was -6.9% ± 7.3% in group F (n = 64) and -1.7% ± 10.1% in group E (n = 48; P = .005) at the first CT and -3.2% ± 10.0% and 1.0% ± 10.6% (P = .10), respectively, at the second CT, indicating recovery of glenoid width in both groups. The postoperative recurrence rate in patients with at least 2 years' follow-up was 14.7% in group F and 14.6% in group E. CONCLUSIONS: In the early stage after ABR, on-the-edge glenoid anchor placement was associated with less glenoid rim erosion than on-the-face anchor placement. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

A Glenoid Defect of 13.5% or Larger Is Not Always Critical in Male Competitive Rugby and American Football Players Undergoing Arthroscopic Bony Bankart Repair: Contribution of Resultant Large Bone Fragment.

PURPOSE: To investigate bone union and postoperative recurrence after arthroscopic bony Bankart repair (ABBR) in male competitive rugby and American football players with a subcritical glenoid defect of ≥13.5% and to compare findings with those in players with a glenoid defect of <13.5%. METHODS: Participants were male competitive rugby or American football players with a glenoid defect and bone fragment who underwent ABBR from July 2011 to December 2018 and were followed for a minimum of 2 years. We investigated the influence of glenoid defect and bone fragment size on bone union and postoperative recurrence after ABBR. RESULTS: We included 45 rugby players and 35 American football players. A total of 38 shoulders were assigned to the small defect group (<13.5%) and 42 to the large defect group (≥13.5%). The complete bone union rate was 47.4% in the small defect group and 71.4% in the large defect group (P = .040), and postoperative recurrence was seen in 13 (34.2%) and 5 shoulders (11.9%), respectively (P = .030). In the small defect group, the bone fragment size was <7.5% in 30 shoulders and ≥7.5% in 8 shoulders; in comparison, the respective numbers were 12 and 30 shoulders in the large defect group, and large fragments (>7.5%) were significantly more common in this group (P < .001). The complete union rate was significantly higher in shoulders with a large fragment (≥7.5%) than in those with a small fragment (<7.5%; 78.9% versus 42.9%, respectively; P = .001). The recurrence rate was 33.3% in shoulders with a small fragment (<7.5%) and 10.5% in shoulders with a large fragment (≥7.5%; P = .017) and was significantly lower in shoulders with a complete union than in those without a complete union (6.3% versus 46.9%, respectively; P < .001). CONCLUSION: The postoperative recurrence rate after ABBR was lower in male competitive rugby and American football players with a large glenoid defect (≥13.5%) than in those with a small glenoid defect (<13.5%) and might be associated with a higher rate of complete bone union of the resultant large bone fragment (≥7.5%). LEVEL OF EVIDENCE: III, case-control study.

Placement of sutures for inside-out meniscal repair: both sutures through meniscal tissue reduces displacement on cyclical loading.

PURPOSE: The inside-out meniscal repair is widely performed to preserve the function of meniscus. In this technique, the outer suture is passed through the capsule as well as the outer meniscus, while the inner suture is inserted into the meniscus. The aim of this study was to biomechanically compare the suture stability between meniscus-meniscus and meniscus-capsule suture methods for the longitudinal meniscal tear with inside-out technique. METHODS: Twenty-seven porcine knees were dissected to maintain the femur-medial capsule/meniscus-tibia complex, and the inner meniscus was cut off along the meniscus circumferential fiber with 3 mm width of the peripheral meniscus preserved. After one needle with a 2-0 polyester suture was inserted into the inner portion of the meniscus, the other needle was inserted through 1) the peripheral meniscus (Group A), 2) capsule just above the meniscus (Group B), and 3) capsule at 10 mm apart from the meniscus-capsule junction (Group C) in the inside-out manner. Then, the suture was manually tied on the capsule. The suture gap at the repair site during 300 times of cyclic loading and the ultimate failure load in the load-to-failure test were measured. The statistical significance of the data between two groups in each combination was considered by Bonferroni correction, following a one-way analysis of variance. RESULTS: In the cyclic loading test, the suture gap was 0.68 ± 0.26 mm in Group A, 1.08 ± 0.36 mm in Group B, and 1.94 ± 0.57 mm in Group C with a significant difference. In the load-to-failure test, the ultimate failure load was 59.1 ± 13.6 N in Group A, 60.0 ± 7.9 N in Group B, and 57.4 ± 4.7 N in Group C, and there was no significant difference. CONCLUSION: The stitching region in the inside-out technique for longitudinal meniscal tear affected the stability of the tear site, and stitching the mid-substance region of the meniscus provides good stability in response to cyclic tensile loading. In addition, the stitching region did not affect the ultimate failure load. CLINICAL RELEVANCE: In the inside-out meniscal repair, the outer suture should be inserted into the remaining peripheral meniscus or the capsule near the meniscus.

Outcomes More Than 2 Years After Meniscal Repair for Longitudinal Tears of the Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Meniscal function after repair of longitudinal tears of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated. PURPOSE: To evaluate not only the clinical outcomes and radiographic findings of patients who underwent repair of longitudinal tears of the LM combined with ACLR but also the healing status of the repaired meniscus and changes in chondral status with second-look arthroscopy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Among 548 patients who underwent primary anatomic ACLR at our institution between 2010 and 2017, 39 who had concomitant longitudinal tears of the LM and underwent repair were studied. During follow-up for more than 2 years, all patients were evaluated clinically (pain, range of motion, swelling, and knee instability) and with imaging (plain radiograph and magnetic resonance imaging [MRI]), and compared with a matched control group (based on age, sex, body mass index, and follow-up period) without any concomitant injuries who underwent ACLR. Measurements on MRI were recorded preoperatively, immediately after surgery, and at final follow-up, and the change in the values over time was assessed. Of the 39 patients in each group, 24 were assessed by second-look arthroscopy with hardware removal 2 years postoperatively. RESULTS: The mean follow-up times of the study and control group were at a mean of 42.4 and 45.4 months, respectively. There were no significant differences in clinical findings, lateral joint space narrowing on radiographs, and chondral status at the lateral compartment between groups, whereas lateral and posterior meniscal extrusion on MRI progressed significantly in the study group (0.43 ± 1.0 mm vs -0.29 ± 1.1 mm, P = .003; 1.9 ± 1.9 mm vs 0.14 ± 1.1 mm, P < .0001, respectively). Second-look arthroscopy revealed complete healing in 12 patients (50%), partial healing in 9 (37.5%), and failure in 3 (12.5%) in the study group, and no new tear in the control group. CONCLUSION: The clinical and imaging outcomes after repair of longitudinal tears of the LM combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at 42 months postoperatively, although meniscal extrusion showed progression on coronal/sagittal MRI. Based on the MRI findings and the result that only half of patients achieved complete healing, meniscal function could not be fully restored even after repair. Although degenerative changes were not apparent, longer-term follow-up is needed.

Comparison of tendon-bone healing between a newly developed ultrasound device and the conventional metallic drill in a rabbit MCL reconstruction model.

BACKGROUND: Ligament reconstructive surgeries demand tunnel creation using an over-drilling technique, though this technique has some problems such as metallic particle liberation or difficulties in tunnel creation other than circular cross-section. Recently, a new ultrasound (US) device for bone excavation to overcome these problems was developed. This study aimed to compare the tendon-bone healing in tunnels created using the new US device to that created using the conventional drill in a rabbit model. METHODS: A total of 72 rabbits underwent a reconstruction for the anterior half of the medial collateral ligament (MCL) using a half of the patellar tendon. For the femoral tunnel creation, a new US device was used in 36 rabbits (US group), while a conventional metallic drill was used for the remaining 36 rabbits (DR group). At 4, 8, and 12 weeks postoperatively, biomechanical (n = 10) and histological (n = 2) evaluations were performed. RESULTS: The ultimate failure load was almost equivalent between the US and DR groups at each period (US/DR; 4 weeks, 50.0 ± 12.8 N/43.4 ± 18.9 N, p = 0.62; 8 weeks, 78.6 ± 11.5 N/77.3 ± 29.9 N, p = 0.92; and 12 weeks: 98.9 ± 33.5 N/102.2 ± 38.3 N, p = 0.80). Pull-out failure from the femoral tunnel was only observed in two rabbits in the US group and one rabbit in the DR group at 4 weeks postoperatively. At 8 and 12 weeks, all specimens had a mid-substance tear. The collagen fiber continuity between tendon and bone occurred 8 weeks postoperatively in both groups and no histological difference was recognized throughout the evaluation period. CONCLUSIONS: The tunnels created using the new US device and the conventional drill had equivalent biomechanical and histological features in tendon-bone healing. The bone excavation technology by the new US device may be applicable in ligament reconstructive surgeries.

Different effects of the lateral meniscus complete radial tear on the load distribution and transmission functions depending on the tear site.

PURPOSE: To compare the effect of the lateral meniscus (LM) complete radial tear at different tear sites on the load distribution and transmission functions. METHODS: A compressive load of 300 N was applied to the intact porcine knees (n = 30) at 15°, 30°, 60°, 90°, and 120° of flexion. The LM complete radial tears were created at the middle portion (group M), the posterior portion (group P), or the posterior root (group R) (n = 10, each group), and the same loading procedure was followed. Finally, the recorded three-dimensional paths were reproduced on the LM-removed knees. The peak contact pressure (contact area) in the lateral compartment and the calculated in situ force of the LM under the principle of superposition were compared among the four groups (intact, group M, group P, and group R). RESULTS: At all the flexion angles, the peak contact pressure (contact area) was significantly higher (lower) after creating the LM complete radial tear as compared to that in the intact state (p < 0.01). At 120° of flexion, group R represented the highest peak contact pressure (lowest contact area), followed by group P and group M (p < 0.05). The results of the in situ force carried by the LM were similar to those of the tibiofemoral contact mechanics. CONCLUSION: The detrimental effect of the LM complete radial tear on the load distribution and transmission functions was greatest in the posterior root tear, followed by the posterior portion tear and the middle portion tear in the deep-flexed position. Complete radial tars of the meniscus, especially at the posterior root, should be repaired to restore the biomechanical function.