Biomechanical Strength of Screw Versus Suture Button Fixation in the Latarjet Procedure: A Cadaver Study.

We compared the strength of screw vs suture button fixation in the Latarjet procedure for shoulder dislocation through biomechanical testing in a cadaver model. Cadavers were assigned randomly to receive screw or suture button fixation (both groups, n=5). The anteroposterior radius of the glenoid was measured, and a bony defect was created on the anteroinferior rim of the glenoid, equal to 25% of the width of the anteroposterior radius of the glenoid surface. The coracoid process was transferred into the newly created bony defect of the glenoid and fixed with two 3.5-mm partially threaded cannulated screws or 2 surgical buttons. All samples underwent tensile testing in the anteroinferior direction. Statistical analysis was performed to compare mean forces at failure between groups (alpha=.05). The mean force at failure was higher in the screw group (295 N; range, 103-534 N) than in the suture button group (133 N; range, 74-270 N) (P=.045). We found no difference between groups in ability to withstand a force of 150 N, which is the reported mean daily force threshold borne by the shoulder (P=.52). Screw fixation withstood a higher failure load than suture button fixation, indicating that screw fixation is a biomechanically superior option in the Latarjet procedure. The fixation methods did not differ in their ability to withstand the mean force borne by the shoulder during activities of daily living; thus, suture button fixation should be considered as an option in the Latarjet procedure. [Orthopedics. 2022;45(6):e321-e325.].

Reverse total shoulder arthroplasty for failed treatment of proximal humerus fractures.

OBJECTIVE: The aim of this study was to evaluate the functional and radiological outcomes and complications of reverse total shoulder arthroplasty (RTSA) for failed treatment of proximal humerus fractures (FTPHF). METHODS: In this retrospective study, 20 patients (17 female, 3 male; mean age = 71.35 years; age range = 54-81 years) who underwent RTSA for FTPHF between 2012 and 2018 were included. The mean follow-up was 37.85 (range: 24-83) months. Outcome measures included shoulder range of motion, Constant score, ASES (American Shoulder and Elbow Surgeons) score, visual analog scale (VAS). Intra-or post-operative complications were also recorded. RESULTS: The mean anterior flexion and external rotation improved from 37.25°±10.59° and 11.05°±4.79° preoperatively to 105.53° ± 9.33 and 22.37° ± 4.12° postoperatively, respectively (P < 0.01 for both). The mean Constant and ASES scores ameliorated from 21.95 ± 3.57 and 18.15 ± 4.69 preoperatively to 61.7 ± 7.6 and 71.18 ± 4.69 at the final follow-up, respectively (P < 0.01 for both). VAS significantly reduced from 6.83 ± 2.04 preoperatively to 1.79 ± 0.61 at the final follow-up (P < 0.01). None of the patients had major complications or required revision. CONCLUSION: Treatment with the RTSA for the FTPHF seems to be an effective treatment method that can provide satisfactory radiological and functional outcomes with low complication rates. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Do Techniques for Hill-Sachs Remplissage Matter in Terms of Functional and Radiological Outcomes?

BACKGROUND: Different techniques are used for the remplissage procedure, including the double-pulley and mattress suture techniques. Both techniques have shown good results; however, it is unclear if one technique is superior. HYPOTHESIS: The remplissage procedure using the double-pulley technique with 2 anchors would have superior functional and radiological outcomes compared with the mattress suture technique with a single anchor. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This study included patients with anterior shoulder instability who were treated using arthroscopic Bankart repair combined with remplissage between 2012 and 2017. A structured questionnaire was used to gather information on the following metrics: Instability Severity Index Score, hyperlaxity, Sugaya index, presence of a Hill-Sachs defect, number of dislocations before surgery, sports participation, radiological measurement of the Hill-Sachs lesion, postoperative range of motion in both shoulders, Rowe score, Walch-Duplay score, American Shoulder and Elbow Surgeons score, and Filling Index Score of Remplissage grade according to magnetic resonance imaging scans at the last follow-up. RESULTS: There were 41 patients included with a mean age of 30 ± 7 years who underwent the Hill-Sachs remplissage procedure using the double-pulley technique with 2 anchors (n = 21; group DA) or the mattress suture technique with a single anchor (n = 20; group SA). At the final follow-up, there were no significant differences between the groups regarding the Instability Severity Index Score (P = .134), the Sugaya index (P = .538), sports participation (P = .41), the radiological measurement of the Hill-Sachs lesion (P = .803), or the Rowe score (P = .182). However, there were significant differences between the groups in the Walch-Duplay score (P = .012), American Shoulder and Elbow Surgeons score (P = .005), and Filling Index Score of Remplissage grade (P = .015), favoring group DA, as well as differences in external rotation in a neutral position (external rotation loss: 9° ± 3° [group SA] vs 12° ± 3° [group DA]; P = .003) and at 90° of abduction (external rotation loss: 8° ± 3° [group SA] vs 11° ± 3° [group DA]; P = .006), favoring group SA. CONCLUSION: In the remplissage procedure, the double-pulley technique provided better filling of the lesion and improvement in functional scores, but external rotation was limited compared with the mattress suture technique.

A comparative study on use of two versus three double-loaded suture anchors in arthroscopic Bankart repair.

OBJECTIVES: This study aims to compare clinical results of repair using two versus three double-loaded suture anchors in arthroscopic Bankart repair. PATIENTS AND METHODS: Between July 2012 and December 2017, a total of 40 patients (38 males, 2 females; mean age: 31.6±8.1; range: 17 to 47 years) who underwent Bankart arthroscopic surgery and were followed for minimum two years were retrospectively analyzed. Group 1 (n=17) underwent arthroscopic Bankart repair with two double-loaded suture anchors, while Group 2 (n=23) underwent repair with three double-loaded suture anchors. Clinical outcomes of the patients and recurrences were compared. RESULTS: At the final postoperative follow-up, a significant improvement was observed in the functional outcomes in all patients. No statistically significant difference was found (p>0.05) in the mean clinical scores of the Constant Shoulder Score between Group 1 (94.2±7.8) and Group 2 (95.4±4.1). There was no significant difference in the mean Rowe scores (Group 1: 95.6±4.6 vs. Group 2: 96.3±3.8, respectively) and external rotation loss (at neutral Group 1: 1.9° vs. Group 2: 2.2°, respectively). Three of our patients had recurrent dislocation during a major traumatic event (n=2 in Group 1 and n=1 in Group 2). CONCLUSION: Our study results suggest that stability is not correlated with the use of either two versus three double-loaded suture anchors in arthroscopic Bankart repairs.

Arthroscopic excision of intraarticular subperiosteal osteoid osteoma of talar neck: A case report.

Osteoid osteoma (OO) is a benign, small, and painful tumor typically seen in the subcortical shaft and metaphysis of the long bones of the lower limb. The occurrence of this type of tumor on the talar neck is rare and may cause limitation of range of motion of the ankle joint. In this article, a 17-year-old male patient had ankle pain and limitation of joint motion accompanied by synovitis. The OO in the intraarticular subperiosteal talar neck was successfully excised arthroscopically and the nidus was completely removed. The diagnosis was confirmed histopathologically in the postoperative period. In this case, we achieved a successful result with surgical treatment of benign bone tumor in the talus with intraarticular excision of the lesion arthroscopically.

The clinical and radiologic outcome of microfracture on arthroscopic repair for full-thickness rotator cuff tear.

BACKGROUND: The persistent incidence of retear despite improvements in techniques led orthopedic surgeons to the application of principles of tissue bioengineering to achieve enhanced repair and functional outcomes. The purpose of this study was to compare clinical and radiologic outcomes of arthroscopic single-row repair augmented with microfracture (SRM) at the greater tuberosity with single-row (SR) and double-row (DR) repair in the treatment of full-thickness rotator cuff tears. MATERIALS AND METHODS: This is a retrospective comparative study. A total of 123 patients were enrolled for arthroscopic repair of full-thickness rotator cuff tears, with 40 patients treated by SR, 44 by SRM, and 39 by DR. The minimum follow-up was 2 years. The primary outcome was retear rate, which was detected by magnetic resonance imaging, and the secondary outcome was functional outcome. RESULTS: The mean age of the patients was 59.2 years, 58.1 years, and 60.6 years in the SR, SRM, and DR groups, respectively. The retear rate was 33%, 14%, and 36% in the SR, SRM, and DR groups, respectively (P = .045). The SRM group had significantly improved functional outcomes compared with the SR and DR groups in terms of the postoperative Constant score and visual analog scale score (P = .001 and .002, respectively). Delta Constant scores were nonsignificant for retear and intact tendons (P = .137). CONCLUSION: SRM has a significantly lower retear rate and better functional outcome than SR and DR repair.

Arthroscopic excision of an intra-articular osteoid osteoma in the elbow joint.

An osteoid osteoma is a rare, small, benign and painful tumour occurring in the extra-articular portion of long bones seen most commonly in the lower extremities. This is a case report of a 23-year-old female patient who underwent arthroscopic resection of an intra-articular osteoid osteoma. The nidus was completely removed by arthroscopic excision. The diagnosis was confirmed by postoperative histopathological analysis. In the case presented we have shown that intra-articular arthroscopy can be successful in the surgical management of benign bony lesions involving the elbow joint. We also present a review of the literature which reports on similar cases or intra-articular disease, preferred methods of surgical management and limitations in histopathological specimen acquisition for diagnosis.

The effects of extracorporeal shock waves on carrageenan-induced Achilles tendinitis in rats: a biomechanical and histological analysis.

OBJECTIVE: The aim of this study was to investigate the influence of low-dose extracorporeal shock waves (ESW) on the healing potential of Achilles tendinitis in the rat. METHODS: The 36 adult Sprague-Dawley rats used in this study were randomly divided into four groups. Group A (n=10) were injected with carrageenan, Group B (n=10) were injected with carrageenan and received ESW, Group C (n=10) received ESW only, and Group D (n=6) was a sham group. Rats were injected with 10 microliters of 3% carrageenan or a saline solution eight times during a one-week period with a subcutaneous needle. One week following the final injection, ESW was applied at a rate of 500 impulses in 5 minutes at 2 bars (comparative to 0.09 mJ/mm²) to rats in Groups B and C. Rats were sacrificed three weeks later. Tensile strength, inflammation, and vascularity and collagen density were measured. RESULTS: Failure of the tendon ultimate loads was significantly lower in the study groups than in the control group (p<0.05). Collagen fiber density was higher in the control group than in the other groups (p=0.59). No other histological differences were found. CONCLUSION: Low-dose ESW has a negative effect on tendon tensile strength in this animal model.

Comparison of repair techniques in small and medium-sized rotator cuff tears in cadaveric sheep shoulders.

OBJECTIVE: The aim of this study was to compare new knotless single-row and double-row suture anchor techniques with traditional transosseous suture techniques for different sized rotator cuff tears in an animal model. METHODS: The study included 56 cadaveric sheep shoulders. Supraspinatus cuff tears of 1 cm repaired with new knotless single-row suture anchor technique and supraspinatus and infraspinatus rotator cuff tears of 3 cm repaired with double-row suture anchor technique were compared to traditional transosseous suture techniques and control groups. The repaired tendons were loaded with 5 mm/min static velocity with 2.5 kgN load cell in Instron 8874 machine until the repair failure. RESULTS: The 1 cm transosseous group was statistically superior to 1 cm control group (p=0.021, p<0.05) and the 3 cm SpeedBridge group was statistically superior to the 1 cm SpeedFix group (p=0.012, p<0.05). The differences between the other groups were not statistically significant. CONCLUSION: No significant difference was found between the new knotless suture anchor techniques and traditional transosseous suture techniques.

Comparison of tunnel expansion and isometric muscle strength after ACL reconstruction with single- or dual-bundle hamstring allograft: a prospective, randomized study.

OBJECTIVE: The aim of this study was to compare tunnel expansion and isokinetic muscle strength after single- and dual-bundle reconstruction of the anterior cruciate ligament (ACL). METHODS: This study included 34 patients who underwent ACL reconstruction in our clinic between November 2007 and March 2008. Eighteen patients (average age: 27.3 years; range: 19 to 35 years) underwent single-bundle ACL reconstruction and sixteen patients (average age: 30.1 years; range: 20 to 40 years) underwent dual-bundle ACL reconstruction. Method selection was determined by draw. Isokinetic hamstring and quadriceps muscle strength was tested preoperatively using Biodex 3. Three-dimensional computed tomography of the knee joint was taken in the 2nd and 3rd postoperative month. The three-dimensional computed tomography and isokinetic muscle strength tests were repeated at the 6th month follow-up. Each tunnel was divided into six equal parts, and the tunnel width in the sagittal and coronal planes was measured and the same points in the axial plane were measured in the tunnel area. RESULTS: No significant difference was found between the single- and dual-bundle reconstructions in isokinetic muscle strength values. No statistically significant difference was detected between the tunnel expansions in 2nd, 3rd and 6th month tomographies following single- and dual-bundle ACL reconstruction. CONCLUSION: Single- and dual-bundle ACL reconstructions seem to provide similar results in terms of early tunnel enlargement and isokinetic muscle strength.

Prospective evaluation of the functional and anatomical results of arthroscopic repair in small and medium-sized full-thickness tears of the supraspinatus tendon.

OBJECTIVE: The purpose of this study was to analyze the relation between tendon integrity and functional results following the arthroscopic treatment of small- and medium-sized rotator cuff tears. METHODS: Arthroscopic repair was performed on 26 consecutive patients (21 women, 5 men;mean age: 55.9 years; range: 33-72 years) with small- and medium-sized tears of the supraspinatus tendon. Patients were postoperatively evaluated at 12 and 24 months using the Constant and UCLA functional outcome scores and ultrasound examinations. RESULTS: The supraspinatus tendon did not heal in nine patients (34.6%) and was partially healed in three (11%), 12 months after surgery. Mean postoperative Constant and UCLA scores of these patients were 73.1 and 27.8, respectively, which were not significantly different from those with an intact tendon on the final follow-up (Constant: 78 and UCLA: 30; p=0.107 and p=0.164). Both rating systems reflected significant improvement with treatment (p<0.01). The mean age of patients with a re-tear was 66.8 years, which was significantly higher than those with an intact repair (54 years; p<0.01). CONCLUSION: The arthroscopic repair of small and medium-sized supraspinatus tendon tears yields good long-term results independent of tendon integrity. Healing potential may be decreased with increased age.

Irreducible dislocation of the knee joint: two-stage treatment.

Closed reduction attempts may be unsuccessful after traumatic knee dislocations on rare occasions. The interposition of the soft tissues on the medial aspect of the joint into the femoral condyle and tibial plateau is shown to be the cause of an unsuccessful reduction. In such cases, open reduction is the recommended method of treatment. In our study, we presented a 16-year-old male with an open knee dislocation after a motorcycle accident. As our closed reduction attempt failed, open joint reduction and repair of the medial collateral ligament and retinaculum was performed in the first stage of treatment. In the second stage, arthroscopic anterior cruciate ligament and posterior cruciate ligament reconstructions were carried out.

Clinical and isokinetic comparison between tenotomy and tenodesis in biceps pathologies.

OBJECTIVES: The purpose of this study to compare clinical and isokinetic results of patients who underwent biceps tenotomy or tenodesis for chronic tenosynovitis. METHODS: Arthroscopic biceps tenotomy, arthroscopy assisted or arthroscopic biceps tenodesis were done in 20 patients who had diagnosis of chronic tenosynovitis and in whom conservative treatment was not helpful. Rotator cuff repair and acromioplasty was performed in 18 patients and acromioplasty alone in two patients in addition to biceps surgery. Arthroscopic biceps tenotomy was done in 10 patients (5 female, 5 male; mean age 63, range 53-75), 10 patients underwent tenodesis out of which arthroscopy assisted biceps tenodesis was done in 8 patients and all arthroscopic biceps tenodesis was done in 2 patients (4 female, 6 male; mean age 57, range 49-66). All patients were evaluated with Constant and UCLA scores preoperatively and postoperatively. The average follow-up of the patients 3,1 years (between 1-8 years). Isokinetically elbow flexion and forearm supination were compared using the Cybex (Biodex 3, Cybex Biomedical System, NY, USA) machine. Pre-operative results of each group were compared with the postoperative results, using Mann-Whitney U test. RESULTS: Preoperative average constant scores of tenotomy group were 64.40, whereas postoperative scores were 89.50 (p=0.002), and preoperative average constant scores of tenodesis group were 62.80, whereas postoperative scores were 86.70 (p=0.003). Preoperative average UCLA scores of tenotomy group were 23.20 whereas postoperative UCLA scores 22.60 (p=0.003), preoperative average UCLA scores of tenodesis group were 30.00 whereas postoperative UCLA scores was 29.20 (p=0.004). In both groups statistically significant improvement of UCLA and Constant scores was detected. Comparison between Constant, UCLA scores and isokinetic measurements of both groups showed no statistically significant difference (p>0.05). No complication was noted. CONCLUSION: In the treatment of chronic tenosynovitis, biceps tenodesis and tenotomy of long head of biceps showed similar clinical, functional, isokinetic and cosmetic results. No Popeye deformity was seen in the tenotomy group.

Tibiocalcaneal arthrodesis with posterior blade plate in diabetic neuroarthropthy.

BACKGROUND: To prevent amputation, achieving successfull ankle artrodesis in diabetic Charcot arthropaty patients is very important. As a salvage procedure, we have used a 95-degree-angled blade plate via a posterior approach to achieve tibiocalcaneal arthrodesis. MATERIALS AND METHODS: Between 2006 and 2008, four diabetic patients with hindfoot Charcot arthropathy underwent talectomy and tibiocalcaneal arthrodesis with an AO 95-degree-angled blade plate via a posterior approach. Two of the patients were male and two were female. The average age was 63 (range, 53 to 70) years. The mean duration of diabetes was 9 (range, 5 to 20) years. All the patients were on hemodialysis. Three of four patients had undergone previous surgeries. The average followup period was 24 (range, 12 to 35) months. RESULTS: Clinical and radiographic fusion was present by 5 (range, 3 to 6) months in three of four patients. In the other patient, a stable fibrous ankylosis was achieved. Clinical outcomes were excellent in three patients, and good in one patient. CONCLUSION: The performance of tibiocalcaneal arthrodesis with the use of blade plate with a posterior approach was a safe and successful surgical method for the treatment of Charcot ankle.

Bone pulsating metastasis due to renal cell carcinoma.

Pulsation on the bone cortex surface is a rare condition. Pulsative palpation of the superficial-located bone tumors can be misperceived as an aneurysm. Fifty-eight-year-old man is presented with pulsating bone mass in his proximal tibia. During angiographic examination, hypervascular masses were diagnosed both at right kidney and at right proximal tibia. Renal cell carcinoma was diagnosed after abdominal CT scan. Proximal tibia biopsy was complicated with projectile bleeding.

[Unicondylar knee arthroplasty in medial unicompartmental osteoarthritis: technical faults and difficulties]. / Diz medial osteoartritinde unikondiler diz protezi: Teknik hatalar ve sorunlar.

OBJECTIVES: The aim of this study is to evaluate both the technical problems of surgery and the clinical and radiologic outcomes of patients treated with unicondylar knee arthroplasty. PATIENTS AND METHODS: Forty-one unicondylar knee prosthesis were performed in 40 patients (3 males, 37 females; mean age 58.2 years; range 44 to 76 years) diagnosed with unicompartmental knee osteoarthritis. Technical problems encountered during surgery were noted. For evaluation of clinical outcomes, the Hospital for Special Surgery (HSS) knee score and WOMAC score were used. Radiologic evaluations were performed using the Oxford Knee Group criteria. RESULTS: The radiologic evaluation determined there was more than 10 degrees varus-valgus malposition in eight patients, more than 2 mm medial tibial overhang in seven patients, the insertion of a femoral component in extension in one patient, and joint distraction in one patient. The patient with joint distraction underwent a total knee replacement after six months because of progressive pain. The mean HSS knee score improved 21 points; perfect results were obtained in 33 patients and good results in seven patients. The mean postoperative WOMAC score was reduced by 18 points, with perfect results in 33 patients, good results in six patients and a moderate result in one patient. The mean follow-up was 19 months (range 9-42). CONCLUSION: Unicondylar knee arthroplasty is a surgical treatment method with a long-term recovery and high frequency of technical faults. Minor errors diagnosed on radiographs do not have an effect on early clinical results. Unicondylar knee arthroplasty is a good alternative surgical technique for appropriately selected patients with medial unicompartmental knee osteoarthritis.

Correlations of isokinetic measurements with tendon healing following open repair of rotator cuff tears.

The aim of this study was to investigate the correlation of tendon integrity following open cuff repairs with functional and isokinetic strength measurements. Twenty-six shoulders of 25 patients were included in this study. At the final follow-up, 14 repairs (53.8%) were intact and 12 repairs (46.2%) had failed on magnetic resonance imaging (MRI). Mean UCLA score at latest follow-up was 28.5 and mean Constant score was 80.3. Constant scores were found to be significantly low for the failed group. Age was found to be significantly related to failed repair. Fatty infiltration stage in the failed repair group was significantly high, and a strong positive correlation for both groups existed pre and postoperatively. When both groups were compared, the failed group was found to have significantly low measurements at extension and internal rotation. Despite high failure rates, functional results were satisfactory. Increased age and fatty infiltration stage decrease success.

Comparison of arthroscopic capsular release in diabetic and idiopathic frozen shoulder patients.

INTRODUCTION: The clinical results of arthroscopic capsular release for frozen shoulder in diabetic (group 1) and idiopathic (group 2) patients were compared. Surgery was performed on 28 shoulders of 26 patients (24 women, 2 men) with frozen shoulder unresponsive to conservative treatment. The mean age was 50 (range 40-65). A total of 14 patients were included in group 1, and 12 were in group 2. The average duration of complaints was 10 and 7 months in groups 1 and 2, respectively. The evaluation of shoulder functions was made according to the University of California, Los Angeles (UCLA) and Constant Scoring Systems. Duration of complete pain relief and for regaining range of motion (ROM) after surgery were also noted in their final follow-up examination. RESULTS: The mean follow-up period was 48.5 and 60.2 months in group 1 and group 2, respectively. There was no significant difference between the two groups in terms of the postoperative duration of complete pain relief and that for regaining ROM (P > 0.05). The duration of complete pain relief was 2.6 and 2.5 months, and regaining of ROM was 1.6 and 1.5 months for groups 1 and 2, respectively. The postoperative UCLA and Constant scores had significant increases in both groups compared to the preoperative ones (P < 0.05). There was a significant difference between the groups in terms of Constant scores (P < 0.05) while there was no difference in terms of UCLA scores (P > 0.05). There was a statistically significant difference in shoulder abduction and internal rotation degrees between the groups (P < 0.05). CONCLUSION: The results of arthroscopic capsular release for frozen shoulder in diabetic patients had less good results in terms of range of motion and Constant-Score. There was no significant difference between the two groups in terms of the duration of pain relief and that of regaining the ROM.

[Elastofibroma dorsi: an unusual cause of shoulder pain]. / Elastofibroma dorsi: Nadir görülen bir omuz agrisi nedeni.

OBJECTIVES: We evaluated patients who underwent surgical treatment for elastofibroma dorsi (ED). METHODS: The study included 13 patients (11 women, 2 men; mean age 54 years; range 43 to 74 years) who were treated surgically for ED that caused persistent symptoms. Involvement was on the right in six patients, on the left in five patients, and bilateral in two patients. All the patients presented with a mass lesion that became apparent at the lower corner of the scapula on shoulder flexion and adduction. The complaints were swelling and pain on the back in nine patients, and a snapping sound on shoulder movements together with pain in four patients. Diagnosis of ED was made by magnetic resonance imaging (n=10) and computed tomography (n=3), with no utilization of preoperative biopsy. Marginal tumor excision was performed in all cases. Evaluation for recurrence was made by ultrasonography. The mean follow-up period was 32 months (range 8 to 90 months). RESULTS: All the masses were located at the inferior corner of the scapula, with adherence to the thorax between the serratus anterior, rhomboid, and latissimus dorsi muscles. The mean size of the surgical specimens was 9 x 6 x 3 cm (range 5 x 3 x 1 to 14 x 8 x 3 cm). Clinical diagnosis was confirmed by histopathologic examination in all cases. All major complaints resolved after surgery. Hematoma occurred in four cases postoperatively, but resolved without the need for surgical intervention. No recurrence was observed. CONCLUSION: Even though ED is a rare clinic entity, it should be recalled while evaluating shoulder pathologies. Marginal excision is adequate for the treatment of patients with sustaining complaints.

Biomechanical and histological comparison of the influence of oestrogen deficient state on tendon healing potential in rats.

Thirty-six female Sprague-Dawley rats were divided into two groups: oophrectomised (oestrogen deficient) rats and sham operated (oestrogen maintained) rats. Rats were sacrificed at six, ten, and 14 weeks. The rats were randomly chosen to have biomechanical evaluation on one side and histological evaluation on the other. Biomechanical testing was performed on an Instron machine to measure peak load. Histological sections were evaluated for cell proliferation, collagen-fibre organisation, fibroblast density, angiogenesis, inflammatory cells, chondroid and osseous metaplasia. Compared with the sham operated group, the oophrectomised group showed a lesser average maximum stress (42.9 N/m(2) versus 33.7 N/m(2)) at six weeks, which was significant (p < .05). Succeeding weeks showed no significant biomechanical differences between the two groups. The sham operated group showed greater inflammatory response, which was statistically significant (p < 0.05), and also revealed greater cell proliferation and density. The results of this study revealed that endogenous oestrogen may improve healing of the Achilles tendon in rats.