Latarjet procedure: biomechanical evaluation of 2-screw coracoid fixation.

BACKGROUND: Coracoid nonunion is a relevant complication following the Latarjet procedure and is influenced by multiple factors, including the method of graft fixation. The purpose of this study was to evaluate and characterize the biomechanical properties of various two-screw fixation constructs used for coracoid graft fixation in the Latarjet procedure. METHODS: Forty model scapulae (Sawbones Inc., Vashon, WA, USA) were used for this study. A 15% anterior inferior glenoid bone defect was created. The coracoid was osteotomized at the juncture of the vertical and horizontal aspects, transferred to the anterior-inferior edge of the glenoid, and fixed with either two 3.5 mm fully threaded cannulated cortical screws, two 3.5 mm fully threaded solid cortical screws, two 3.5 mm partially threaded cannulated screws, or two 4.5 mm partially threaded malleolar screws (MS). Biomechanical testing was performed with an Instron material testing machine (Instron Corp., Norwood, MA, USA) by applying loads to the lateral aspect of the transferred coracoid graft. The constructs were preconditioned with nondestructive cyclical loading (0N-20N) to determine construct stiffness. After 100 cycles of dynamic loading, the construct was loaded to failure to determine ultimate failure load, yield displacement, and mode of failure. RESULTS: All failures were associated with plastic deformation of the screws and coracoid graft fracture. There was a significantly lower initial stiffness for partially threaded cannulated screws compared to MS (186 ± 49.3 N/mm vs. 280 ± 65.5 N/mm, P = .01) but no significant differences among the other constructs. There was no difference in ultimate failure load (P = .18) or yield displacement (P = .05) among constructs. CONCLUSION: Two screw coracoid fixation of the coracoid in a simulated classic Latarjet procedure with 3.5 mm fully threaded cortical and cannulated screws is comparable to 4.5 mm MS in strength, stiffness, and displacement at failure. On the other hand, partially threaded 3.5 mm cannulated screws provide inferior fixation stiffness and could potentially affect clinical outcomes.

Intra-articular biomechanical environment following modified Bristow and Latarjet procedures in shoulders with large glenoid defects: relationship with postoperative complications.

BACKGROUND: Although coracoid transfers including the modified Bristow and Latarjet procedures are widely used to treat anterior shoulder instability, the influence of the choice of procedure on the biomechanical outcomes is not well characterized. We aimed to clarify the intra-articular stress distribution following these 2 procedures using 3-dimensional finite-element analysis and to investigate the role of stress distribution in the pathophysiology of postoperative complications. METHODS: Overall, 6 male patients aged 17-47 years with unilateral anterior shoulder instability were recruited. Computed tomographic digital imaging and communications in medicine (CT-DICOM) data of the contralateral (healthy) shoulder of each patient was obtained and used for developing the 3-dimensional normal glenohumeral joint model. A 25% bony defect was created in the anterior glenoid rim where the coracoid process was transferred in the standing and lying-down positions to create the Bristow and Latarjet models, respectively. The arm position was set as 0° or 90° abduction. The Young moduli of the humerus and scapula were calculated using CT data, and set as 35.0 MPa and 113.8 GPa for the articular cartilage and inserted screw, respectively. A compressive load (50 N) was applied to the greater tuberosity toward the center of the glenoid, and a tensile load (20 N) was applied to the tip of the coracoid in the direction of conjoint tendon. Elastic analysis was used to determine the equivalent stress distribution. RESULTS: A significant reduction in mean equivalent stress was observed within the glenoid cartilage for both models (P = .031); however, a new stress concentration appeared within the grafted coracoid-facing region of the humeral-head cartilage in both models. The proximal half of the coracoid graft exhibited lower equivalent stress than the distal half in 5 of the 6 Latarjet models, whereas the proximal half showed higher equivalent stress than the distal half in all 6 Bristow models. High stress concentration was identified at the midpoint of the inserted screw in Bristow models. DISCUSSION AND CONCLUSIONS: Intra-articular stress distribution may explain the different rates of postoperative complications associated with the modified Bristow and Latarjet procedures. New stress concentration within the humeral-head cartilage might contribute to the development of glenohumeral osteoarthritis following both procedures. Stress shielding in the proximal part of the coracoid graft might contribute to osteolysis following the Latarjet procedure. Surgeons should be aware of the risk of breakage of the inserted screw following the modified Bristow procedure.

Proximal-medial part in the coracoid graft demonstrates the most evident stress shielding following the Latarjet procedure: a simulation study using the 3-dimensional finite element method.

BACKGROUND: Although the osteolysis of the coracoid graft is frequently observed after the Latarjet procedure particularly in its proximal part, its pathomechanism is not well understood. METHODS: Three-dimensional finite element glenohumeral joint models were developed using CT-DICOM data of 10 normal shoulders. A 25% bony defect was created on the anterior glenoid rim, and the coracoid process was transferred flush with the glenoid cartilage using 2 half-threaded screws. In the hanging arm as well as in the 90° abducted positions, a compressive load (50 N) was applied to the greater tuberosity toward the center of the glenoid and a tensile force (20 N) was applied to the coracoid tip along the direction of the conjoint tendon. Next, elastic analysis was performed, and the distribution patterns of the equivalent stress as well as the maximum principal stress were compared among 4 parts (proximal/distal and medial/lateral) of the coracoid graft. RESULTS: Both the equivalent stress and the maximum principal stress were reduced in the proximal half of the coracoid graft. A high stress concentration was observed in the lateral aspect of the coracoid graft particularly in the 90° abducted position. The proximal-medial part demonstrated the lowest equivalent stress as well as the maximum principal stress for both arm positions, which were significantly lower than those in the distal 2 parts. CONCLUSION: In the Latarjet procedure, the proximal-medial part of the coracoid graft demonstrated the most evident stress shielding, which may play an important role in postoperative osteolysis.

Intraoperative and anatomic dimensions of the coracoid graft as they pertain to the Latarjet-Walch procedure.

BACKGROUND: Our objective was to study the anatomic and intraoperative coracoid measurements with an aim to closely replicate the Latarjet-Walch technique and find the similarities and dissimilarities in our population. METHODS: In the cadaveric study, 20 shoulders in 10 fresh cadavers were dissected, and the coracoid length, width, and thickness were measured. In the intraoperative study, 10 patients underwent the classic Latarjet procedure according to the Walch technique. The harvested coracoid graft was analyzed for the length of the coracoid, the distance of the inferior hole from the lateral margin of the coracoid graft, and the width of the coracoid graft at the inferior and superior hole. RESULT: The average distance from the tip of the coracoid to the trapezoid insertion was 25.4 mm (standard deviation [SD], 1.7 mm). The mean width of the undersurface of the coracoid was 14.2 mm. The average length of the graft after harvesting was 25.1 mm (SD, 1 mm). The average distance between the lateral border and the inferior hole was 5.5 mm (SD, 1.1 mm). We used 25-mm malleolar screws in 3 shoulders and 30-mm malleolar screws in 7 shoulders. CONCLUSION: The"7-mm" rule of Walch could be followed in our population. The medial surface width of the coracoid in our Indian morphology was an average of 7 mm; hence, malleolar screws of 30 and 25 mm were used to fix the graft on the glenoid.

Fate of coracoid grafts after the Latarjet procedure: will be analogous to the original glenoid by remodelling.

PURPOSE: To evaluate the location, magnitude, and change over time of osteolysis of coracoid grafts after Latarjet procedure. METHODS: This is a retrospective study of 54 patients (55 shoulders) who underwent the Latarjet procedure. Three-dimensional computed tomography (CT) scans were performed preoperatively, immediately postoperatively, and at follow-up (mean 7.7 and 31.7 months postoperative). "En face" views of the glenoid, size of glenoid defect and changes in the glenoid surface area postoperatively were measured relative to the area of an assumed outer-fitting circle. On the oblique sagittal planes, location and subsequent severity of osteolysis of the graft at follow-up were documented. RESULTS: The mean glenoid surface area increased significantly from 79.7 ± 4.8% of the original circle preoperatively to 111.3 ± 8.0% immediately postoperatively. At 7.7 and 31.7 months of follow-up, glenoid surface area decreased to 102.2 ± 6.0% and 100.3 ± 5.3%, respectively. Osteolysis occurred on the outer side of the graft in all cases, but did not occur on the inner side. Maximum osteolysis was observed in the superior third of the graft (78.5 ± 17.1%), followed by the middle third (15.8 ± 10.4%), and the inferior third (8.0 ± 5.1%). No significant difference in magnitude of osteolysis was observed between 7.7 and 31.7 months of follow-up. CONCLUSION: Osteolysis of the grafted coracoid mainly occurred on the outer side of the superior portion, resulting in reshaping of the rectangular shape of graft coracoids after Latarjet procedure. Coracoid graft remodelling was almost completed approximately 8 months postoperatively to reach the original glenoid dish with no further changes thereafter. These results may help surgeons to understand changes of grafts after the surgery. LEVEL OF EVIDENCE: IV.

Coracoid graft union: a quantitative assessment by computed tomography in primary and revision Latarjet procedure.

BACKGROUND: The goal of the Latarjet procedure is restoration of shoulder stability enabled by accurate graft positioning and union. This study aimed to establish a reproducible method of quantitatively assessing coracoid graft osseous union percentage (OUP) using computed tomography (CT) scans and to determine the effect of other factors on the OUP. MATERIALS AND METHODS: Postoperative CT scans of 41 consecutive patients treated with the open Latarjet procedure (37% primary, 63% revision) for anterior glenohumeral instability were analyzed for the OUP, position of the graft, and screw type and angle. Two musculoskeletal radiologists independently examined the images 2 times, and intraobserver and interobserver reliability was calculated using intraclass correlation coefficient (ICC). RESULTS: Mean OUP was 66% (range, 0%-94%) using quantitate methods, with good intraobserver reliability (ICC = 0.795) and interobserver reliability (ICC = 0.797). Nonunion and significant graft resorption was found in 2 patients. No significant difference was found in the mean OUP in the primary (63%) vs. revision Latarjet procedure (67%). Grafts were flush in 39%, medial in 36%, and lateral in 8%. The medial and neutral graft position was associated with slightly higher OUP (72% and 69%) compared with lateral (65%). OUP was higher when the superior screw angle was less than 17° and the inferior screw angle was less than 24°. This difference did not reach statistical significance. Screw type was not associated with significant difference in OUP. CONCLUSION: Quantitative assessment of osseous union of the graft using a reproducible method that we introduced showed similar OUP in the primary and revision Latarjet procedure.

Three-dimensional volume measurement of coracoid graft osteolysis after arthroscopic Latarjet procedure.

BACKGROUND AND HYPOTHESIS: The Latarjet procedure has been shown to be a reliable method to prevent recurrent anterior shoulder instability. Coracoid bone graft osteolysis is a potential catastrophic complication and can lead to recurrent instability. The purpose of our study is to present a novel quantitative method to measure the amount of coracoid bone osteolysis using 3-dimensional (3D) computed tomography (CT) scan imaging. MATERIALS AND METHODS: This is a prospective study with 15 patients (16 shoulders) who underwent an arthroscopic Latarjet procedure. Three-dimensional CT scans were obtained at 6 weeks and 6 months. Using volumetric analysis, we quantified the amount of bone loss using our described method. Interobserver reliability and intraobserver reliability were calculated. RESULTS: On the basis of our new volumetric analysis of the arthroscopic Latarjet procedure using 3D CT scans, we found that the superior half of the coracoid bone graft undergoes a significant amount of osteolysis at 6 months postoperatively. The interobserver reliability and intraobserver reliability were excellent. DISCUSSION: This study presents a reproducible method to quantify and compare coracoid bone graft osteolysis after an arthroscopic Latarjet procedure. We also developed a description system that may be used for comparison studies. To our knowledge, this is the first method that quantifies the amount of coracoid bone graft osteolysis using more accurate 3D CT scanning. CONCLUSION: The 3D analysis we propose is a valid method to measure the amount of coracoid bone graft osteolysis after an arthroscopic Latarjet procedure. Our description system may guide the surgeon regarding possible revision surgery when faced with significant osteolysis of the coracoid bone graft.

Graft osteolysis and recurrent instability after the Latarjet procedure performed with bioabsorbable screw fixation.

HYPOTHESIS AND BACKGROUND: The Latarjet procedure is a reliable treatment of recurrent anterior shoulder instability. The coracoid process is usually fixed with metallic screws; however, these can lead to irritation and the necessity for hardware removal and also can produce artifacts on imaging studies. The use of resorbable screws could avoid these complications. The purpose of this study was to assess the clinical results of the Latarjet procedure performed with bioabsorbable screws in addition to healing of the graft and resorption of the screws. METHODS: In 2009, we performed a prospective study (case series, LEVEL OF EVIDENCE: IV) of 11 patients (12 shoulders) who underwent a Latarjet procedure fixed with resorbable screws. Each patient was observed clinically and had a computed tomography scan at 3 months and 2 years of follow-up. RESULTS: Every graft healed at 3-month follow-up. At 2-year follow-up, 4 patients had at least one instability episode, and one underwent a revision surgery. Three of these 4 patients were unhappy or disappointed. The Walch-Duplay score was excellent or good for 7 shoulders and medium or poor for 5. Screw resorption appeared complete in every case. No drill hole enlargement was observed. Every drill hole was partially filled with bone. Of 12 shoulders, 8 (66.67%) were associated with a severe osteolysis and an almost complete disappearance of the graft. CONCLUSION: Coracoid graft osteolysis, previously reported after the Latarjet procedure, appears to be exacerbated with a risk of complete disappearance of the graft when the procedure is performed with the bioabsorbable screws used in this study.

Suspensory fixation for bone transfer procedures in shoulder instability is superior to screws in an angled construct: a biomechanical analysis.

Background: The Latarjet procedure is a common bony augmentation procedure for anterior shoulder instability. Historically, screw fixation is used to secure the coracoid graft to the anterior glenoid surface; however, malpositioning of the graft leads to oblique screw insertion that contributes to complications. Suture buttons (SBs) are a more recent fixation technique that have not been studied alongside standard screw fixation in the context of biomechanical models of angulated fixation. This study aims to compare the biomechanical strength of single and double, screw and SB fixation at various levels of angulation. Methods: Testing was performed using polyurethane models from Sawbones. The graft piece was secured with screw fixation (Arthrex, Naples, FL, USA) or suspensory button (ABS Tightrope, Arthrex, Naples, FL, USA). Single or double constructs of screws and SBs were affixed at 0°, 15°, and 30° angles to the face of the glenoid component. An aluminum testing jig held the samples securely while a materials testing system applied loads. Five constructs were used for each condition and assessed load to failure testing. Results: For single fixation constructs, suspensory buttons were 60% stronger than screws at 0° (P < .001), and 52% stronger at 15° (P = .004); however, at 30°, both were comparable (P = .180). Interestingly, single suspensory button at 15° was equivalent to a single screw at 0° (P = .310). For double fixation, suspensory buttons (DT) were 32% stronger than screws at 0° (P < .001) and 35% stronger than screws at 15° (P < .001). Both double fixation methods were comparable at 30° (P = .061). Suspensory buttons at 15° and 30° were equivalent to double screws at 0 (P = .280) and 15° (P = .772), respectively. Conclusion: These measurements indicate that the suspensory button has a significantly higher load to failure capacity over the screw fixation technique, perpendicularly and with up to 15° of angulation. These analyses also indicate that the suspensory button fixation offers superior strength even when positioned more obliquely than the screw fixation. Therefore, suspensory button fixation may confer more strength while offering greater margin for error when positioning the graft.

Determining optimal length of coracoid graft in the modified Bristow procedure for anterior shoulder instability: A three-dimensional finite element analysis.

BACKGROUND: There is a lack of consensus concerning the coracoid graft length in the modified Bristow procedure. OBJECTIVE: We attempted to determine the optimal graft length using the three-dimensional finite element method. METHODS: In a shoulder model with a 25% anterior glenoid defect, a coracoid graft of varying lengths (5, 10, 15, and 20 mm) was fixed using a half-threaded screw. First, a compressive load of 500 N was applied to the screw head to determine the graft failure load during screw tightening. Next, a tensile load (200 N) was applied to the graft to determine the failure load due to biceps muscle traction. RESULTS: In the screw compression, the failure loads in the 5-, 10-, 15-, and 20-mm models were 252, 370, 377, and 331 N, respectively. In the tensile load applied to the coracoid graft, the failure load exceeded 200 N for both the 5- and 10-mm models. CONCLUSION: The 5-mm graft had a high risk of fracture during intraoperative screw tightening. As for the biceps muscle traction, the 5- and 10-mm-grafts had a lower failure risk than the 15- and 20-mm-grafts. Therefore, we believe that the optimal length of the coracoid graft is 10 mm in the modified Bristow procedure.

Arthroscopic Salvage Procedure for Iatrogenic Conjoint Tendon Avulsion Fracture Following Arthroscopic Latarjet Procedure Using Double Sling Fixation Technique - A Case Report.

Introduction: We present a case report of an iatrogenic conjoint tendon avulsion fracture following arthroscopic Latarjet and salvage technique to address the complication with a novel double sling technique. Case Report: A 16-year-old male patient who presented with recurrent instability of the right shoulder was counseled for an arthroscopic Latarjet procedure, taking account of critical glenoid bone loss and his contact sporting activities. An intraoperative coracoid tip fracture occurred, which was managed with the double sling technique. At 1-year follow-up, the patient has made a good recovery with a full range of movements and a stable shoulder; the CT scans showed a well-approximated coracoid tip fragment. Conclusion: Iatrogenic intraoperative coracoid graft fractures during arthroscopic Latarjet can be managed depending on the site of the fracture and quality of the bone. The double sling fixation technique helps in maintaining the sling action of the conjoint tendon in patients with recurrent instability.

Does preoperative glenoid bony defect determine final coracoid graft positioning in arthroscopic Latarjet?

Background: It has been demonstrated that the accurate positioning of the graft is key to restoring shoulder stability and preventing future arthrosis development. Preoperative anteroinferior glenoid bone loss is frequently encountered when performing a Latarjet, and it has not been determined yet if the amount of bony defect can influence graft positioning. The aim of the study was to determine if a preoperative glenoid bony defect has an influence on the final coracoid graft position in the arthroscopic Latarjet procedure. Methods: Fifty-five patients who underwent the arthroscopic Latarjet procedure were included, with a minimum follow-up of 2 years. There were 51 men (92.7%). Mean age was 29.1 (SD 7.63). Western Ontario Shoulder Instability Index, Rowe, and Single Assessment Numeric Evaluation scores were fulfilled. All measurements were performed by a musculoskeletal radiologist based on a multiplanar bidimensional CT scan. Dimensions of the glenoid, glenoid defect, and glenoid track were calculated. Position of the graft was evaluated in the axial (distance to glenoid surface, angulation of the graft and screws) and sagittal planes (percentage of the coracoid graft below the equator) as described by Kany et al and Barth et al respectively. Results: There was a glenoid defect in 41 patients (74.5 %). Mean width of the defect was 4.32 mm (SD 3.08) which represented 15.3% of the native glenoid surface (SD 10.8). 78.2% of the patients were offtrack preoperatively, and 11.9% remained offtrack postoperatively. The final glenoid diameter with the graft was 32.1 mm (SD 4.34). Mean distance from the graft to the glenoid at 50% height was 1.1 mm (SD 2.19 mm) and at 25% height was 1.31 mm (SD 2.05). Mean angulation of the superior and inferior screws were 26.9° (SD 8.2°) and 27.1° (SD 7.35°), respectively. In 81.8% of the cases, the graft was deemed to be flush with the glenoid. The percentage of the coracoid graft under the equator of the glenoid was 71.2 % (SD 21.8). There was not a statistically significant difference in screw angulation or graft positioning in the axial plane when comparing patients who had a glenoid defect with those who did not, or depending on the size (P > .05). Percentage of graft below the equator was, however, lower in patients without bony defect (P = .04). Conclusion: This study showed that accurate position of the coracoid graft is achieved in the presence of a glenoid bony defect. In the cases of intact glenoid, the height of the graft should be carefully evaluated.

Anterior Shoulder Instability in a Young Individual with Concomitant Coracoid Process Fracture Treated with the Latarjet Procedure - A Rare Case Report.

Introduction: Coracoid fracture occurs with shoulder instability due to direct humeral head impaction. Incidence coracoid fracture with shoulder dislocation is rare amounts to 0.8-2%. We encountered clinical challenge of unique combination of both shoulder instability and coracoid fracture. This technical note will describe the treatment of the same. Case Report: A 23-year-old male suffering from recurrent shoulder dislocation sustained coracoid fracture. Further evaluation showed glenoid defect of 25%. Magnetic resonance study showed on track lesion with Hill-Sach lesion of 9 mm, labral defect anteriorly with no associated rotator cuff tear. The patient was managed with open Latarjet procedure with fracture coracoid fragment with conjoint tendon as graft. Conclusion: Our purpose of reporting this technical note is to provide an option of dealing both instability and coracoid fracture in single sitting and usage of coracoid fractured fragment as an excellent graft of choice in acute presentation. However, certain limitations such as adequacy of graft in size and shape do exist operating surgeon which must be aware of the same.

Biomechanical Evaluation of the 2 Different Levels of Coracoid Graft Positions in the Latarjet Procedure for Anterior Shoulder Instability.

Background: In the Latarjet procedure, the ideal placement of the coracoid graft in the medial-lateral position is flush with the anterior glenoid rim. However, the ideal position of the graft in the superior-inferior position (sagittal plane) for restoring glenohumeral joint stability is still controversial. Purpose: To compare coracoid graft clockface positions between the traditional 3 to 5 o'clock and a more inferior (for the right shoulder) 4 to 6 o'clock with regard to glenohumeral joint stability in the Latarjet procedure. Study Design: Controlled laboratory study. Methods: A total of 10 fresh-frozen cadaveric shoulders were tested in a dynamic, custom-built robotic shoulder model. Each shoulder was loaded with a 50-N compressive load while an 80-N force was applied in the anteroinferior axes at 90° of abduction and 60° of shoulder external rotation. Four conditions were tested: (1) intact, (2) 6-mm glenoid bone loss (GBL), (3) Latarjet procedure fixed at 3- to 5-o'clock position, and (4) Latarjet procedure fixed at 4- to 6-o'clock position. The stability ratio (SR) and degree of lateral humeral displacement (LHD) were recorded. A 1-factor random-intercepts linear mixed-effects model and Tukey method were used for statistical analysis. Results: Compared with the intact state (1.77 ± 0.11), the SR was significantly lower after creating a 6-mm GBL (1.14 ± 0.61, P = .009), with no significant difference in SR after Latarjet 3 to 5 o'clock (1.51 ± 0.70, P = .51) or 4 to 6 o'clock (1.55 ± 0.68, P = .52). Compared with the intact state (6.48 ± 2.24 mm), LHD decreased significantly after GBL (3.16 ± 1.56 mm, P < .001) and Latarjet 4 to 6 o'clock (5.48 ± 3.39 mm, P < .001). Displacement decreased significantly after Latarjet 3 to 5 o'clock (4.78 ± 2.50 mm, P = .04) compared with the intact state but not after Latarjet 4 to 6 o'clock (P = .71). Conclusion: The Latarjet procedure in both coracoid graft positions (3-5 and 4-6 o'clock) restored the SR to the values measured in the intact state. A more inferior graft position (fixed at 4-6 o'clock) may improve shoulder biomechanics, but additional work is needed to establish clinical relevance. Clinical Relevance: An inferior coracoid graft fixation, the 4- to 6-o'clock position, may benefit in restoring normal shoulder biomechanics after the Latarjet procedure.

Influence of Graft Positioning during the Latarjet Procedure on Shoulder Stability and Articular Contact Pressure: Computational Analysis of the Bone Block Effect.

The Latarjet procedure is the most popular surgical procedure to treat anterior glenohumeral (GH) instability in the presence of large anterior glenoid bone defects. Even though the placement of the bone graft has a considerable influence on its efficacy, no clear indications exist for the best graft position. The aim of this study was to investigate the influence of the medial-lateral positioning of the bone graft on the contact mechanics and GH stability due to the bone block effect. Four finite element (FE) models of a GH joint, with a 20% glenoid bone defect, treated by the Latarjet procedure were developed. The FE models differed in the medial-lateral positioning of the bone graft, ranging from a flush position to a 4.5 mm lateral position with respect to the flush position. All graft placement options were evaluated for two separate shoulder positions. Anterior GH instability was simulated by translating the humeral head in the anterior direction, under a permanent compressive force, until the peak translation force was reached. Joint stability was computed as the ratio between the shear and the compressive components of the force. The lateralization of the bone graft increased GH stability due to the bone block effect after a 3 mm lateralization with respect to the flush position. The increase in GH stability was associated with a concerning increase in peak contact pressure due to the incongruous contact between the articulating surfaces. The sensitivity of the contact pressures to the medial-lateral positioning of the bone graft suggests a trade-off between GH stability due to the bone block effect and the risk of osteoarthritis, especially considering that an accurate and consistent placement of the bone graft is difficult in vivo.

Open Classic Latarjet Procedure Performed Using Freehand Technique-Surgical Technique and Outcome.

INTRODUCTION: Latarjet procedure is commonly performed for recurrent anterior shoulder instability with glenoid side bone loss. Classic Latarjet procedure can be performed using specially designed drill guides, jigs, or by freehand technique. Here we have described a technical note on classic Latarjet procedure performed with freehand technique utilizing simple rulers and caliper. The functional and radiological outcomes of our patients have also been analysed. MATERIAL AND METHODS: 149 open classic Latarjet procedures were performed using our technique between March 2015 and July 2018. The mean age of the patients was 32.95 years (Range 22-59 years). The functional outcome of the patients was measured using Western Ontario Shoulder Instability (WOSI) and Oxford Shoulder Instability Score (OSIS) at 2 years of follow-up. Screw and graft positioning were studied in 24 consecutive patients with a postoperative computed tomography (CT) scan. RESULTS: There was no incidence of recurrent subluxation or dislocation post-surgery. Mean OSIS score increased from 15.63 ± 3.20 preoperatively to 42.44 ± 3.88 postoperatively (p value < 0.05). WOSI score decreased significantly from 62.54% ± 8.24 to 10.26 ± 6.33 postoperatively at 2-year follow-up (p value < 0.05). Postoperative CT scan also showed satisfactory screw placement in all patients. CONCLUSION: Open Latarjet procedure performed using freehand technique provides good functional and radiological outcomes in patients with recurrent anterior shoulder instability with glenoid side bone loss. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s43465-021-00385-7.

Functional Outcome of Open Latarjet Procedure in Non-Athletic Middle-Aged Patients.

INTRODUCTION: The movement and steadiness of the shoulder joint is due to both the dynamic and static stabilisers. Recurrent anterior shoulder instability is common due to the Bankart lesion or the Hill Sachs lesion. The bone loss and soft tissue failure due to these lesions causing instability is well compensated by Latarjet procedure which acts by triple blocking effect of the bone graft, the sling effect of the conjoint tendon of subscapularis and the ligament of the coracoacromial ligament stump. MATERIALS AND METHODS: Middle-aged patients with recurrent anterior shoulder dislocation and a mid-range instability on clinical assessment with an isolated glenoid bone loss of 20% or Bankart lesion with engaging Hill Sachs lesion were selected for the study. The surgical procedure included a subscapularis split to expose the glenoid. The coracoid graft harvested was prefixed with Kirschner wires and placed flush over the glenoid ensuring no medial or lateral overhang and fixed with 4.0mm cancellous screws with the washer. The functional outcome was measured with the ROWE score and ASES score and the movements were evaluated. RESULTS: A total of 24 patients fulfilled the inclusion criteria. Post-operatively at final follow-up, the mean ROWE score was 97.08 ±8.45 and the mean ASES score was 94.4±9.10. One patient had screw breakage as a complication and another had restriction of movement which was managed with physiotherapy. CONCLUSION: Open Latarjet is an effective procedure for recurrent anterior shoulder instability in non-athletic middle-aged patients as a excellent functional outcome was achieved with this technique. We therefore recommend open Latarjet as an alternative to arthroscopic treatment in developing countries where patient affordability and the availability of the resources are the issues.

Basic morphological characteristics of coracoid grafts obtained by open and arthroscopic Latarjet techniques: A comparative study.

BACKGROUND: A knowledge of the anthropometric characteristics of the coracoid graft (CG) that can be obtained by the open and arthroscopic Latarjet techniques may be beneficial in the preoperative planning and intraoperative decision making for coracoid osteotomy and transfer. We have not found any study that compared the morphology of the CG that can be obtained from open and arthroscopic Latarjet techniques. The purpose of this study was to verify if the basic anthropometric characteristics of CGs are equivalent. HYPOTHESIS: We hypothesize that the basic anthropometric characteristics of the CGs are similar. METHODS: Twenty fresh-frozen human paired cadaveric shoulder specimens that had been randomly distributed in two groups of 10 specimens each were used. Two surgeons, each with experience in performing the open and arthroscopic Latarjet technique, performed these procedures in each of the respective groups (OG, open group; AG, arthroscopic group). A CT scan was performed. Using the volume rendering technique, a metric analysis of the volume, area and length of the CG were performed, evaluated and statistically analysed. RESULTS: There were no significant differences in length (p=0.162) (mean length, 22.6mm for OG and 23.6mm for AG). There were significant differences in the volume (p=0.031) and area (p=0.007) of the CG, being lower in the OG (mean volume, 2.8 cm3 for OG and 3.6 cm3 for AG; mean area, 9.9 cm2 for OG and 12.8 cm2 for AG). No significant differences were observed by sex or laterality. CONCLUSION: The mean lengths of the CGs that were obtained by each technique are equivalent. However, the areas and volumes of the grafts are different, being lower in the open surgery. These differences have not been an impediment to perform the technique. Our results corroborates that consolidation is more related to the preparation and placement than to the anthropometric characteristics of the CG. No significant differences were observed by sex or laterality. LEVEL OF EVIDENCE: Basic Science.

Bone union of the transferred coracoid graft is the key factor affecting the extent of postoperative graft changes and the clinical results following the modified Bankart and Bristow procedure: a computed tomography scan study.

BACKGROUND: The extent of postoperative changes in the coracoid process grafted during the modified Bankart and Bristow procedure remains unclear. The purpose of the present study was to quantify the postoperative changes in bone surface area as assessed on computed tomography, as well as to clarify the impact of such changes on the clinical results. METHODS: Twenty-three shoulders of 21 subjects who underwent the modified Bankart and Bristow procedure were retrospectively analyzed. Computed tomography images were obtained immediately after surgery and at the final follow-up. The changes in bone surface area of the grafted coracoid process were measured on computed tomography slices in the proximity of the screw bore. Clinical outcomes were evaluated in terms of the Rowe, Walch-Duplay, and simple shoulder test scores. RESULTS: Bone area increased in 15 shoulders (65.2%) and decreased in eight shoulders (34.8%). Bone area increased by 51.3% in shoulders with bone union in the superior part of the coracoid process graft, with no significant differences between the superior and inferior sides of the graft regarding the rate of change in bone surface area (41.4% vs. 68.9% increase). However, in shoulders with bone union in the inferior part of the coracoid process graft, the rate of change in bone area differed significantly between the superior and inferior sides of the graft, exhibiting a 42.3% decrease on the superior side and 39.8% increase on the inferior side. In shoulders with no bone union, bone area decreased by 29.5% (17.4% vs. 39.3% decrease on the superior and inferior side, respectively), whereas the Rowe and Walch-Duplay scores were significantly lower than those noted in shoulders with bone union. CONCLUSIONS: Postoperative bone formation and bone resorption in the coracoid process grafted during the modified Bankart and Bristow procedure depend on whether and where bone union occurs. Graft non-union is associated with inferior clinical results.

Can a Drill Guide Improve the Coracoid Graft Placement During the Latarjet Procedure? A Prospective Comparative Study With the Freehand Technique.

BACKGROUND: One of the factors that can affect the success of the Latarjet procedure is accurate coracoid graft (CG) placement. HYPOTHESIS: The use of a guide can improve placement of the CG and screw positioning in the sagittal and axial planes as compared with the classic open ("freehand") technique. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 49 patients who underwent a Latarjet procedure for the treatment of recurrent anterior shoulder instability were prospectively included; the procedure was performed with the freehand technique in 22 patients (group 1) and with use of a parallel drill guide during screw placement in 27 patients (group 2). All patients underwent a postoperative computed tomography scan with the same established protocol. The scans were used to evaluate and compare the position of the CG in the sagittal and axial planes, the direction of the screws (α angle), and overall contact of the graft with the anterior surface of the glenoid after the 2 surgical techniques. RESULTS: The CG was placed >60% below the native glenoid equator in 23 patients (85.2%) in group 2, compared with 14 patients (63.6%) in group 1 (P = .004). In the axial plane, the position of the CG in group 2 patients was more accurate (85.2% and 88.9% flush) at the inferior and middle quartiles of the glenoid surface (P = .012 and .009), respectively. Moreover, with the freehand technique (group 1), the graft was in a more lateral position in the inferior and middle quartiles (P = .012 and .009, respectively). No differences were found between groups 1 and 2 regarding the mean α angle of the superior (9° ± 4.14° vs 11° ± 6.3°, P = .232) and inferior (9.5° ± 6° vs 10° ± 7.5°, P = .629) screws. However, the mean contact angle (angle between the posterior coracoid and the anterior glenoid surface) with the freehand technique (3.8° ± 6.8°) was better than that of the guide (8.55° ± 8°) (P = .05). CONCLUSION: Compared with the classic freehand operative technique, the parallel drill guide can ensure more accurate placement of the CG in the axial and sagittal planes, although with inferior bone contact.