Hamstring Tendon Regeneration After Harvest for Anterior Cruciate Ligament Reconstruction: A Systematic Review

Muscle Morphology Does Not Solely Determine Knee Flexion Weakness After Anterior Cruciate Ligament Reconstruction with a Semitendinosus Tendon Graft: A Combined Experimental and Computational Modeling Study

The distal semitendinosus tendon is commonly harvested for anterior cruciate ligament reconstruction, inducing substantial morbidity at the knee. The aim of this study was to probe how morphological changes of the semitendinosus muscle after harvest of its distal tendon for anterior cruciate ligament reconstruction affects knee flexion strength and whether the knee flexor synergists can compensate for the knee flexion weakness. Ten participants 8-18 months after anterior cruciate ligament reconstruction with an ipsilateral distal semitendinosus tendon autograft performed isometric knee flexion strength testing (15°, 45°, 60°, and 90°; 0° = knee extension) positioned prone on an isokinetic dynamometer. Morphological parameters extracted from magnetic resonance images were used to inform a musculoskeletal model. Knee flexion moments estimated by the model were then compared with those measured experimentally at each knee angle position. A statistically significant between-leg difference in experimentally-measured maximal isometric strength was found at 60° and 90°, but not 15° or 45°, of knee flexion. The musculoskeletal model matched the between-leg differences observed in experimental knee flexion moments at 15° and 45° but did not well estimate between-leg differences with a more flexed knee, particularly at 90°. Further, the knee flexor synergists could not physiologically compensate for weakness in deep knee flexion. These results suggest additional factors other than knee flexor muscle morphology play a role in knee flexion weakness following anterior cruciate ligament reconstruction with a distal semitendinosus tendon graft and thus more work at neural and microscopic levels is required for informing treatment and rehabilitation in this demographic.

Strength and Functional Outcomes Following Achilles Tendon Reconstruction With Hamstring Tendon Autograft Augmentation

BACKGROUND

The proposed advantages of hamstring autograft reconstruction when compared to alternative procedures, such as flexor hallucis longus (FHL) transfer, V-Y lengthening, and allograft reconstruction, are improved healing and reproduction of normal tendon biomechanics and reduced morbidity within the foot and ankle. In this study, we examined the effect of Achilles tendon reconstruction using hamstring autografts on strength and functional outcomes.

METHODS

Patients who underwent Achilles repair with a hamstring autograft for insertional or midsubstance tendinopathy, delayed diagnosis of rupture, or infection after primary repair were evaluated for inclusion. Forty-six patients were identified; 12 further augmented with an FHL transfer are included in the analysis. Isokinetic testing was completed with a Biodex dynamometer under supervision of a physical therapist masked to surgical side. Pre- and postoperative Foot and Ankle Outcome Scores (FAOS, before March 2016) or Patient-Reported Outcomes Measurement Information System (PROMIS, after March 2016) surveys were collected.

RESULTS

For knee flexion, peak torque was not significantly different when comparing operative and nonoperative sides at 180 degrees/second (45.38 Nm vs 45.96 Nm; P = .69) nor at 300 degrees/second (44.2 Nm vs 47.02 Nm; P = .069). Knee extension absolute peak torque was only found to be significantly weaker on the operative side at the faster testing (75.5 Nm vs 79.56 Nm; P < .05). Peak ankle plantarflexion torque was significantly weaker on the operative side at both the slower speed (60 degrees/second: 39.9 Nm vs 48.76 Nm; P < .005) and the faster speed (120 degrees/second: 31.3 Nm vs 40.7 Nm; P < .001). Average power for ankle plantarflexion did not differ significantly from the operative side to the nonoperative side in the slower test (26.46 W vs 27.48 W; P = .60) but did significantly differ on the faster test (32.13 W vs 37.63 W; P = .041). At an average of 19.9 months postoperation, all physical function and pain-related patient-reported outcome scores showed clinically and statistically significant improvement.

CONCLUSION

Achilles reconstruction with a hamstring autograft ± FHL transfer allowed patients with severe Achilles pathology to return to good subjective function, with modest deficits in calf strength compared with the uninjured side. Overall knee flexion strength did not appear impaired. These results suggest that hamstring autograft reconstruction is a viable method to treat these complex cases involving a lack of healthy tissue, allowing patients to return to symptom-free physical function and athletic activity.

LEVEL OF EVIDENCE

Level IV, case series.

Moment arm and torque generating capacity of semitendinosus following tendon harvesting for anterior cruciate ligament reconstruction: A simulation study

Altered semitendinosus (ST) morphology and distal tendon insertion following anterior cruciate ligament reconstruction (ACLR) may reduce knee flexion torque generating capacity of the hamstrings via impaired ST force generation and/or moment arm. This study used a computational musculoskeletal model to simulate mechanical consequences of tendon harvest for ACLR on ST function by modeling changes in ST muscle tendon insertion point, moment arm, and torque generating capacity across a physiological range of motion. Simulated ST function was then compared between ACLR and uninjured contralateral limbs. Magnetic resonance imaging from 18 individuals with unilateral history of ACLR involving a hamstring autograft was used to analyse bilateral hamstring muscle (ST, semimembranosus, bicep femoris long head and short head) morphology and distal ST tendon insertion. The ACLR cohort was sub-grouped into those with and without ST regeneration. For each participant with ST regeneration (n = 7), a personalized musculoskeletal model was created including postoperative remodeling of ST using OpenSim 4.1. Knee flexion and internal rotation moment arms and torque generating capacities of hamstrings were evaluated. Bilateral differences were calculated with an asymmetry index (%) ([unaffected limb-affected limb]/[unaffected limb + affected limb]*100%). Smaller moment arms or knee torques within injured compared to uninjured contralateral limbs were considered a deficit. Compared to uninjured contralateral limbs, ACLR limbs with tendon regeneration (n = 7) had minor reductions in knee flexion (5.80% [95% confidence interval (CI) = 3.97-7.62]) and internal rotation (4.92% [95% CI = 2.77-7.07]) moment arms. Decoupled from muscle morphology, altered ST moment arms in ACLR limbs with tendon regeneration resulted in negligible deficits in knee flexion (1.20% [95% CI = 0.34-2.06]) and internal rotation (0.24% [95% CI = 0.22-0.26]) torque generating capacity compared to uninjured contralateral limbs. Coupled with muscle morphology, ACLR limbs with tendon regeneration had substantial deficits in knee flexion (19.32% [95% CI = 18.35-20.28]) and internal rotation (15.49% [95% CI = 14.56-16.41]) torques compared to uninjured contralateral limbs. Personalized musculoskeletal models with measures of ST distal insertion and muscle morphology provided unique insights into post-ACLR ST and hamstring function. Deficits in knee flexor and internal rotation moment arms and torque generating capacities were evident in those with ACLR even when tendon regeneration occurred. Future studies may wish to implement this framework in personalized musculoskeletal models following ACLR to better understand individual muscle function for injury prevention and treatment evaluation.

Free tendon grafts for surgical management of chronic tears of the main body of the Achilles tendon: a systematic review

PURPOSE

After four weeks from injury, tears of the Achilles tendon are considered chronic. Their management is challenging, and the use of a graft is suggested when the gap between proximal and distal stumps is greater than 6 cm. The present study systematically reviews the outcome of free tendon grafts in chronic ruptures of the Achilles tendon, evaluating clinical outcomes, complications and return to sport.

METHODS

The present study was conducted according to the PRISMA 2020 guidelines. PubMed, Google Scholar, Embase, and Web of Science databases were accessed in February 2023. All the published clinical studies reporting clinical outcome, return to sport and complications of free tendon grafts used the treatment of chronic rupture of the midportion of the Achilles Tendon were accessed. The mean CMS (Coleman Methodology Score) of 65.7 suggested an overall good quality of the available published articles, attesting to the low risk of bias.

RESULTS

Data from 22 articles (368 patients with a mean age of 47 years) were retrieved. The average time from rupture to surgery was 25.1 week. At last follow-up, the AOFAS (American Orthopaedic Foot and Ankle Surgery) and ATRS (Achilles Tendon Total Rupture Score) scores improved of 33.8 (P = 0.0004), and 45.1 points (P = 0.0001) respectively. Return to activity was reported in 105 patients, and 82 (78.1%) had no activity limitations, while 19 (18.1%) had limited recreational but not daily activity limitations, and 4 (3.8%) reported limitations in daily activities. Return to sport data was reported in six studies, and 45 of 93 (48.4%) patients returned to sport at an average of 22.6 weeks.

CONCLUSION

In chronic tears of the Achilles tendon, with a gap of at least 6 cm, free tendon grafts allow predictable return to sport and acceptable recovery function.

LEVEL OF EVIDENCE

Level IV.

Semitendinosus muscle morphology in relation to surface electrode placement in anterior cruciate ligament reconstructed and contralateral legs

The semitendinosus tendon is commonly harvested as graft tissue for anterior cruciate ligament reconstruction (ACLR). Although the semitendinosus tendon can regenerate following harvesting, ACLR results in substantial reductions in semitendinosus muscle size and length, potentially complicating electrode placement for electromyography. The purpose of this study was to assess whether the most commonly used electrode placement [recommended by the “Surface Electromyography for Non-Invasive Assessment of Muscles” (SENIAM) project] is appropriate for measuring semitendinosus electromyograms after ACLR. In nine participants (unilateral ACLR with a semitendinosus graft), B-mode ultrasonography was used to bilaterally determine (i) the semitendinosus muscle-tendon junction position and the state of tendon regeneration (latter for the ACLR leg only) and (ii) the anatomical cross-sectional area (ACSA) of the semitendinosus muscle at the SENIAM-recommended electrode placement site at rest and during isometric maximal voluntary contraction (MVC) at two knee joint angles. Depending on the contraction state and joint angle, the semitendinosus muscle had retracted past the recommended placement site in 33–78% of ACLR legs, but not in any contralateral legs. The ACSA of semitendinosus was smaller both at rest and MVC in the ACLR compared to contralateral leg. The ACSA for both legs decreased at MVC compared to rest and at deep compared to shallow knee flexion angles, likely due to sliding of the muscle under the skin. These results suggest SENIAM guidelines are likely unsuitable for recording surface electromyograms from the semitendinosus muscle after tendon harvesting for ACLR as the muscle of interest may not be within the electrode detection volume.

Return-to-Sport Outcomes After Primary Ulnar Collateral Ligament Reconstruction With Palmaris Versus Hamstring Tendon Grafts: A Systematic Review

Background

Ulnar collateral ligament (UCL) reconstruction is the current gold standard of treatment for overhead athletes with a symptomatic, deficient UCL of the elbow who have failed nonoperative treatment and wish to return to sport (RTS) at a high level. The palmaris longus and hamstring tendons are common graft choices, but no study has analyzed the existing literature to assess whether one graft is superior to the other.

Purpose

To systematically report on the outcomes of UCL reconstruction using palmaris and hamstring autografts.

Study Design

Systematic review; Level of evidence, 4.

Methods

A combination of the terms "ulnar collateral ligament," "valgus instability," "Tommy John surgery," "hamstring," and "palmaris longus" were searched in PubMed, Embase, and the Cochrane Library. RTS and return-to-same-level (RSL) rates, patient-reported outcomes, and complications were included for analysis. We used the modified Coleman Methodology Score and risk-of-bias tool for nonrandomized studies to assess the quality of the included studies.

Results

This review included 6 studies (combined total of 2154 elbows) that directly compared palmaris and hamstring graft use in UCL reconstruction. Follow-up ranged from 24 to 80.4 months, and the mean patient age across all studies was 21.8 years. The mean RSL across all studies and grafts was 79.0%, and the mean RTS was 84.1%, consistent with results previously reported in the literature. The mean RTS and RSL rates for the palmaris graft group were 84.6% and 82%, respectively; the hamstring graft group showed mean RTS and RSL rates of 80.8% and 80.8%. Meta-analysis revealed no significant difference in RSL between the 2 graft groups (odds ratio, 1.06; 95% CI, 0.77-1.46). The combined complication rate of the included studies was 18.2%, with failure rates ranging from 0% to 7.1%.

Conclusion

Results of this review indicated that both palmaris and hamstring tendon grafts are viable options for primary UCL reconstruction. Graft choice should be determined by a combination of patient and surgeon preference.

Distal avulsion of reconstituted hamstring tendons

PURPOSE

Hamstring tendon autograft (semitendinosus and gracilis) is the most commonly used graft in anterior cruciate ligament (ACL) reconstruction. Distal hamstring tendons avulsion is a rare condition, and this paper describes a previously unreported injury, local management of this rare injury pattern, and the existing literature regarding treatment options.

METHODS

Two cases are presented of distal hamstring avulsion from the tibia of reconstituted tendons, together with additional 12 cases of distal hamstrings tendon avulsion. Functional outcomes following treatment of this injury are presented, together with a literature review of management options.

RESULTS

Early surgical reattachment using suture anchor fixation was performed and excellent results were achieved in 93% of cases (13 out of 14 patients). Patient-reported outcome measures demonstrated a median Marx score 14.5 (IQR 4) and median SHORE score 34.5 (IQR 4). The mean time to surgery was 22 days (range 5-60), with mean time to return to sport at pre-injury level 5.5 months (range 2.5-12).

CONCLUSIONS

Distal hamstring tendon avulsion is a rare condition, with no consensus regarding optimal management options. Acute surgical repair leads to excellent results, with a return to pre-injury level of sporting activity.

LEVEL OF EVIDENCE

IV.

Is there significant regeneration of the hamstring tendons after harvest for ACL reconstruction? A systematic review of literature

BACKGROUND

Regeneration potential of Hamstring tendons after harvest assumes significant clinical relevance as its use has become widespread today. Methods which best assess the regeneration, extent and type of regeneration, plus issues related to functional loss are important for the surgeon to know. This review looks at the literature to find answers to the above questions.

PURPOSE

To summarize the evidence in support of hamstring tendon regeneration, and the most appropriate modality for evaluation of regeneration. Additionally, to evaluate the regeneration in terms of complete or partial, extent and its impact on strength deficit and functional outcomes.

METHODS

We did a systematic review of literature through specified search engines and identified 30 of 285 studies to be relevant (19 prospective and 11 retrospective).

RESULTS

Evaluation of above data suggests tissue regeneration at harvest sites does occur (78.9% of semitendinosus and 42.7% of gracilis tendons), but this regeneration is variable. No established definition of regeneration exists; MRI is an adequate tool to identify regeneration, while biopsy is confirmative. USG is a cost-effective screening method and can document distal progress of regenerate. Semitendinosus and gracilis tendons regenerate at different rates and extents, and often fuse together, but there is no evidence to state that one regenerates better than the other. Proximal retraction of the muscle-tendon junction occurs, along with some atrophy, which affects function to a variable extent. Strength deficits may persist, but they may not convert to significant functional deficits.

CONCLUSION

There is variable hamstring regeneration after harvest, with poorly defined definition of "regeneration". Some changes in the muscle itself, abnormal distal insertion and absence of regeneration in some are documented, along with strength deficits. Although overall functional deficits have been reported to be minimal, a definite change in the anatomy of the medial hamstrings is a factor to be kept in consideration. More information is needed about the long-term consequences.

Fibular Collateral Ligament Reconstruction Graft Options: Clinical and Radiographic Outcomes of Autograft Versus Allograft

PURPOSE

To compare varus knee stability and clinical outcomes between patients who underwent fibular collateral ligament reconstruction (FCLR) or lateral collateral ligament (LCL) reconstruction with autografts versus allografts when undergoing concomitant anterior cruciate ligament reconstruction (ACLR).

METHODS

All patients who underwent primary ACLR and concomitant FCLR from 2010 to 2017 performed by a single surgeon (R.F.L.) were retrospectively identified. Clinical characteristics and graft choices for FCLR were collected. Patients with a minimum 2-year follow-up for clinical outcome scores and 6-month stress radiographs were included. Patients with any other ligamentous procedure or revision ACLR were excluded.

RESULTS

We identified 69 primary ACLR with concomitant FCLR patients who met the inclusion criteria. Fifty patients underwent FCLR with semitendinosus autografts, and 19 with allografts. There were no significant side-to-side differences (SSDs) in lateral compartment gapping on varus stress x-rays between the 2 cohorts (allograft, 0.49 mm; autograft, 0.15 mm, P = .22), and no FCLR failures. There were no significant differences between autograft and allograft groups at minimum 2-year outcomes for 12-Item Short Form mental or physical composite score (SF12 MCS, P = .134; SF12 PCS, P = .642), WOMAC total (P = .158), pain (P = .116), stiffness (P = .061), or activity (P = .252); International Knee Documentation Committee (IKDC) (P = .337), Tegner (P = .601), Lysholm (P = .622), or patient satisfaction (P = .218). There were no significant differences in clinical knee stability between groups at an average follow-up of 3.6 years (P = 1.0).

CONCLUSION

There were no differences in varus stress laxity 6 months postoperatively or clinical outcome scores at ≥2 years postoperatively between patients having FCL reconstructions with either autograft or allograft. This study demonstrates that both hamstring autografts and allografts for FCL reconstructions offer reliable and similar radiographic and clinical results at short-term follow-up.

LEVEL OF EVIDENCE

III, retrospective comparative trial.

Operative Outcome of Side-Locking Loop Suture Technique Accompanied by Autologous Semitendinosus Tendon Grafting for Chronic Rupture of Achilles Tendon

Background:

The purpose of this retrospective study was to clarify the operative outcomes of the side-locking loop suture (SLLS) technique accompanied by autologous semitendinosus tendon grafting for chronic Achilles tendon rupture.

Methods:

A chart review was conducted of consecutive patients treated with the SLLS technique at our department from 2012 to 2017. Postoperatively, a below-knee splint was applied for 2 weeks in 20 degrees of plantar flexion and then active range of motion exercise was started. Partial weightbearing exercise was allowed at 4 weeks according to patient tolerance, and full weightbearing without crutches was allowed at 8 weeks. The American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score and the Achilles tendon rupture score (ATRS) were used to evaluate clinical outcomes preoperatively and at the final follow-up.

Results:

Ten patients (6 men, 4 women) were included in the analysis. Mean AOFAS ankle-hindfoot scale score increased significantly from 64.2 ± 5.6 points preoperatively to 95.0 ± 5.3 points at the final follow-up ( P < .001). The mean ATRS also increased significantly from 29.8 ± 4.4 points to 86.2 ± 7.7 points, respectively ( P < .001). Mean time between surgery and ability to perform 20 continuous double-leg heel raises of the operated foot was 13.5 ± 3.4 (range 10-18) weeks. One patient complained of postoperative hypoesthesia in the foot, which had spontaneously resolved by 3 months after surgery.

Conclusion:

The SLLS technique accompanied by autologous semitendinosus tendon grafting provided successful operative outcomes for patients with chronic Achilles tendon rupture regardless of the size of the defect, and thus long-term orthotic use was not needed after surgery.

Level of Evidence:

Level IV, retrospective case series.

Ipsilateral free semitendinosus graft with interference screw fixation for surgical management of insertional acute Achilles tendon tears

INTRODUCTION

Very distal tears of the Achilles tendon are uncommon, and poor quality tendinous tissue of the calcaneal stump can compromise healing. Little has been published about the characteristics and surgical management of such injuries. We present a surgical technique, developed by the senior author, to restore continuity of the gastrosoleus-Achilles tendon-calcaneus complex using a free ipsilateral semitendinosus graft, and clinical outcomes of a case series of 28 consecutive patients. Our hypothesis was that this is a safe technique, and patients can return to pre-injury occupation and athletic activities.

PATIENTS AND METHODS

A total of 28 patients (mean age 46 years) underwent minimally invasive reconstruction using a free ipsilateral semitendinosus graft for acute insertional rupture of tendo Achillis. The procedure required two small incisions along the course of the Achilles tendon, and one posteromedial incision at level of the ipsilateral knee to harvest the semitendinosus tendon. Patients were assessed at minimum 2 years (range, 2-2.5 years) following the index procedure.

RESULTS

The median Achilles tendon Rupture Score (ATRS) at the latest follow-up was 88. Two patients developed a superficial wound infection. All patients returned to their preinjury occupation, whilst 22 out of 28 patients (79%), returned to their preinjury level of physical activity at a mean of 6.7 months after surgery, reporting good or excellent overall satisfaction in 88.5% of cases.

CONCLUSION

This minimally invasive technique was safe, and allowed most of patients to return to preinjury daily and sport activities within 9 months from surgery.

Do Outcomes or Subsequent Injuries Differ After Ulnar Collateral Ligament Reconstruction With Palmaris Versus Hamstring Autograft?

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) is a successful procedure in professional baseball players. It is unclear whether graft choice affects results.

PURPOSE

Determine performance and rate of return to sport (RTS) in professional baseball players after UCLR and compare performance and RTS rate, as well as injury rates, between players who underwent UCLR with hamstring versus palmaris autograft.

HYPOTHESIS

A high RTS rate exists in professional baseball players after UCLR, with no significant difference in injury rates, RTS rates, or performance specifically related to primary outcome performance variables-WHIP ([walks + hits]/innings pitched), fielding independent pitching (FIP), and wins above replacement (WAR)-between those who undergo UCLR with palmaris versus hamstring autograft.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All professional baseball players who underwent UCLR with hamstring autograft between 2010 and 2015 were included. Surgical details were gathered from operative reports. Players with hamstring UCLR were compared with a matched control group of players who underwent UCLR with palmaris autograft.

RESULTS

Overall, 195 players underwent UCLR with hamstring autograft. No differences in RTS rates or timing to RTS were found between the hamstring and palmaris groups. Significantly more subsequent injuries to the contralateral lower extremity were seen in the hamstring group versus the palmaris group (25 vs 13, respectively) ( P = .040). More subsequent injuries to the upper extremity were found in the palmaris group versus the hamstring group (73 vs 55, respectively), although this difference was not significant ( P = .052). No consistent differences in performance metrics upon RTS existed between hamstring and palmaris groups, although both groups significantly declined in many performance metrics after surgery. Both hamstring and palmaris groups showed a decline postoperatively in WAR (0.86 vs 0.35 and 1.23 vs 0.34, respectively) and WHIP (1.33 vs 1.44 and 1.36 vs 1.51, respectively); FIP did not decline (4.56 vs 5.27 and 4.51 vs 4.53, respectively). No significant difference in WAR, WHIP, or FIP existed between groups postoperatively.

CONCLUSION

Baseball players who underwent UCLR with hamstring autograft were more likely to sustain a subsequent lower extremity injury, whereas those who underwent UCLR with palmaris autograft had a trend toward sustaining more upper extremity injuries. No difference in performance or RTS rates existed between groups. Both groups significantly declined in WAR and WHIP after UCLR.

ASSESSMENT OF THE REGENERATION CAPACITY OF SEMITENDINOSUS AND GRACILIS TENDONS

Objectives:

To evaluate the regenerative capacity of gracilis (G) and semitendinosus (ST) tendons, to examine the sensitivity and specificity of signs and symptoms in the assessment of hamstring tendons, and to assess the thickness and insertion site of regenerated tendons.

Methods:

Thirty sequential knees were subjected to anterior cruciate ligament reconstruction with semitendinosus and gracilis tendons. After surgery, the patients were followed up clinically with physical examination and magnetic resonance imaging (MRI).

Results:

Overall, 36.66% of the tendons were visible on MRI, whereas 83.33% were palpable. On MRI, the distal insertion site of the regenerated semitendinosus tendon was visible proximal to the landmark of the medial femoral condyle in 28%, at the same level in 16%, and distally in 56% of the cases. Gracilis tendon insertion was visible proximally in 36.66% of cases, at the same level in 10%, and distally in 53.33%. Eleven knees exhibited complete regeneration.

Conclusion:

Partial or total regeneration of the ST and G tendons was apparent on MRI. Palpation is effective for evaluating regeneration of the ST and G tendons; however, MRI is still the gold standard. ST and G tendons regenerated completely in only a small percentage of patients, limiting reuse as a graft in cases with new ligament injuries of the knee. Level of Evidence II, Prospective comparative study.

The Long-Term Outcome After Early and Late Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare long-term clinical and radiographic outcomes in patients undergoing either early (group A) or late (group B) surgery after anterior cruciate ligament (ACL) injury.

METHODS

ACL reconstruction using hamstring tendon autografts was performed in 30 patients in group A (median age, 23 years; range, 17-49 years) and 31 patients in group B (median age, 27 years; range, 17-38 years). The patients in group A were operated on within 5 months (median, 3 months; range, 2-5 months) of injury, whereas those in group B were operated on more than 24 months (median, 30 months; range, 24-48 months) after injury. The follow-up period was 10 years (median, 117 months [range, 77-222 months] in group A and 129 months [range, 77-206 months] in group B; P = .44). Multiple objective clinical evaluation tests and patient-reported outcome measures were obtained preoperatively and at follow-up. At follow-up, radiographic assessments of knee osteoarthritis (OA) bilaterally were performed.

RESULTS

The frequency of meniscectomy at the index operation was significantly lower in group A (20%) than in group B (52%) (P = .01). There were no significant differences between the groups in terms of Tegner and Lysholm scores and laxity tests both preoperatively and at follow-up. Both groups improved over time in terms of Tegner and Lysholm scores (P < .05). At follow-up, significantly more medial-compartment OA in the index knee was found in group B than in group A (P = .037) according to the Ahlbäck classification system. The index knee showed significantly more OA than the contralateral knee in both groups (P < .01).

CONCLUSIONS

Patients who underwent early ACL reconstruction required significantly fewer meniscectomies at the index operation than patients who underwent late reconstruction and showed significantly less OA on the medial side of the knee 10 years after reconstruction. However, no significant differences were found between the groups in terms of clinical assessments.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Hamstring Autograft for Foot and Ankle Applications

BACKGROUND

Hamstring tendon autografts may be used for foot and ankle surgeries, although reports on their effectiveness and morbidity in the foot and ankle literature are limited. We studied a cohort of patients who underwent hamstring harvest for foot and ankle applications, hypothesizing that morbidity to the knee would be limited.

METHODS

We studied a cohort of patients who underwent hamstring autograft for foot or ankle applications by a fellowship-trained sports and foot and ankle surgeon since 2011. Thirty-seven patients underwent isokinetic strength testing using a dynamometer an average of 38 months postoperatively. The average patient age was 45 ± 16 (range, 18-78) years, and 54% were women. Peak flexion and extension torque as well as flexion and extension torque at 30, 70, and 90 degrees of flexion were collected at 2 different testing speeds, 180 and 300 degrees/s. t tests were used for all comparisons.

RESULTS

At follow-up, 32 patients (86%) reported no pain at the harvest site; the remaining 5 patients reported mild to moderate symptoms. No patients were dissatisfied, and all would recommend the surgery to someone else. Flexion strength at higher degrees of flexion was significantly lower compared with extension strength as well as compared with flexion strength at lower degrees of flexion, when testing was performed at lower speed ( P < 0.05).

CONCLUSIONS

When used for foot and ankle surgery, hamstring autografts resulted in high patient satisfaction with minimal donor site morbidity. While knee flexion strength was decreased at higher degrees of flexion, this finding did not appear to be clinically significant.

LEVEL OF EVIDENCE

Level IV, case series.

Higher hamstring-to-quadriceps isokinetic strength ratio during the first post-operative months in patients with quadriceps tendon compared to hamstring tendon graft following ACL reconstruction

PURPOSE

The aim of this study was to compare isokinetic quadriceps and hamstring muscle strength in patients following anterior cruciate ligament (ACL) reconstruction who received either hamstring (HT) or quadriceps (QT) tendon autografts at two time intervals within the first year after surgery.

METHODS

One hundred twenty-four patients, 81 males (age 22.0 ± 6.2 years) and 43 females (age 20.9 ± 8.7 years), participated in this study. ACL reconstruction was performed with either quadriceps tendon autografts (QT; n = 61) or hamstring tendon autografts (HT; n = 63). Two isokinetic muscle strength tests (t1: 5.5 ± 1.2 months; t2: 7.6 ± 1.6 months) were performed at an angular velocity of 60°/s in both the injured and contralateral knees. An independent t test as well as a two-factor analysis of variance with repeated measurements was used. The significance level was set at p < 0.05.

RESULTS

A statistically significant lower knee extensor strength was observed in the QT group within one year after surgery (p < 0.001). Additionally, data showed a significant higher H/Q ratio in QT patients compared to the HT group at t1 (p < 0.001) and t2 (p = 0.001) as well as a significant effect over time (p < 0.001) and interaction effect of time and graft (p = 0.007). Side-to-side values for extensor muscle strength were significantly (p < 0.001) greater in HT graft patients, while QT patients showed significantly (p < 0.001) greater values for flexor muscle strength at both time points of isokinetic testing, respectively.

CONCLUSION

The results of this study indicate that graft choice has an impact on extensor strength in the first months after ACL reconstruction; however, there is no impact on flexor strength. The finding of a higher H/Q ratio in patients with QT grafts within the first months following surgery is possibly of clinical relevance. This may potentially be associated with lower stress on the maturing ACL graft. Furthermore, normal thigh strength can be restored over time.

LEVEL OF EVIDENCE

III.

Operative treatment for the painful posterior thigh after hamstring autograft harvesting

Background

Semitendinosus (ST) is widely used autograft in anterior cruciate ligament reconstructions (ACLR). Although tendon harvesting is a common procedure, some patients exhibit pain, cramping and dysfunctional at posterior thigh after the ACLR. The formation of the newly regenerated neotendon could be compromised by a new injury or too rapid rehabilitation. We present this clinical entity and the developed surgical technique and share our experience in treatment of these patients.

Methods

Ten patients underwent operation where the harvested, retracted and loose muscle (9 ST, 1 gracilis) was reattached again. The delay to the diagnosis and the outcome of the procedure were recorded. Cases were followed and magnetic resonance images (MRI) were included from 2 cases for the demonstration of postoperative healing.

Results

Six ST and the gracilis patients with prolonged symptoms had good results and returned to their normal activity level. Preoperative MRI showed increased signal intensity and edema of the harvested and retracted muscles as the sign of compromised healing of the neotendon. Postoperatively, these MRI findings were resolved.

Conclusions

In high activity level patients with chronic posterior thigh pain and cramping of the harvested muscle, the stabilization procedure of the poorly healed muscle belly could lead to beneficial outcome.

Level of evidence

IV. Case series.

Identification of a Remodeled Neo-tendon After Arthroscopic Latarjet Procedure

PURPOSE

To macroscopically, histologically, and radiologically describe a time-dependent remodeling process of a neo-tendon or -ligament in the shoulder after the arthroscopic Latarjet procedure.

METHODS

During follow-up surgery after the arthroscopic Latarjet procedure, 17 shoulders in 16 patients were evaluated for a remodeled tendon-like structure. The mean overall follow-up period was 27.4 months. The mean time between the arthroscopic Latarjet procedure and revision was 11.6 months. All shoulders were evaluated with magnetic resonance imaging, and seven histologic specimens were obtained during revision surgery.

RESULTS

A distinct, oriented strand of tissue was found in 16 of 17 shoulders on revision surgery. Postoperative magnetic resonance imaging analyses showed a signal-free, longitudinal tendon-like structure originating at the tip of the acromion, traversing the space of the former subcoracoid bursa to attach in the course of the transposed conjoint tendon or the proximal short head of the biceps. Histologic analysis of seven specimens showed a characteristic timeline of remodeling.

CONCLUSIONS

A tendon- or ligament-like structure is remodeled between the anterior bottom tip of the acromion and the transposed coracoid process in a time-dependent manner after the arthroscopic Latarjet procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Neuromuscular Coordination Deficit Persists 12 Months after ACL Reconstruction But Can Be Modulated by 6 Weeks of Kettlebell Training: A Case Study in Women's Elite Soccer

The aim of the present single-case study was to investigate the effect of 6 weeks' kettlebell training on the neuromuscular risk profile for ACL injury in a high-risk athlete returning to sport after ACL reconstruction. A female elite soccer player (age 21 years) with no previous history of ACL injury went through neuromuscular screening as measured by EMG preactivity of vastus lateralis and semitendinosus during a standardized sidecutting maneuver. Subsequently, the player experienced a noncontact ACL injury. The player was screened again following postreconstruction rehabilitation, then underwent 6-week kettlebell training, and was subsequently screened again at 6-week follow-up. Prior to and after postreconstruction rehabilitation the player demonstrated a neuromuscular profile during sidecutting known to increase the risk for noncontact ACL injury, that is, reduced EMG preactivity for semitendinosus and elevated EMG preactivity for vastus lateralis. Subsequently, the 6-week kettlebell training increased semitendinosus muscle preactivity during sidecutting by 38 percentage points to a level equivalent to a neuromuscular low-risk profile. An ACL rehabilitated female athlete with a high-risk neuromuscular profile changed to low-risk in response to 6 weeks of kettlebell training. Thus, short-term kettlebell exercise with documented high levels of medial hamstring activation was found to transfer into high medial hamstring preactivation during a sidecutting maneuver.

Anterior cruciate ligament reconstruction-rehabilitation research methodological quality: a systematic review with world region comparisons

PURPOSE

A systematic review and world region comparison of combined ACL reconstruction-rehabilitation studies was performed.

METHODS

Studies that combined ACL surgical-rehabilitative management published between January 1990 and June 2014 were evaluated. The combined terms "rehabilitation" and "anterior cruciate ligament reconstruction" or "ACL reconstruction" were used to search the CINAHL Plus, Cochrane Library, MEDLINE, PEDro, and PubMed databases. A total of 5920 studies were initially identified. Inclusion criteria reduced this total to 299 studies that underwent abstract review. Following this, 155 studies underwent full text review and 109 met all inclusion criteria for Modified Coleman Methodology Score (MCMS) evaluation.

RESULTS

Overall, MCMS were 74.0 ± 17 (mean ± standard deviation). Europe had slightly greater MCMS than North America (P = 0.041). Specific MCMS components that displayed significant world region differences included use of an independent investigator (Europe > North America and Asia; P = 0.047), including a patient-completed written assessment (Europe > North America and Asia; P = 0.009), allowing the patient to complete the assessment without medical, surgical, or rehabilitation personnel intervention (Europe > North America and Asia; P = 0.009), and use of well-described subject selection or inclusion criteria (Europe > North America and Asia; P = 0.004). Tegner Activity Scale (P = 0.042) and VAS-Pain Scale (P = 0.007) use was greater in Europe compared with other world regions. Primary rehabilitation theme frequency was comparable between world regions (n.s.).

CONCLUSION

Regional research methodological quality differences were observed. Europe displayed a slightly greater MCMS for combined ACL reconstruction-rehabilitation studies. With this information, research groups can design better team-based approaches to ensure that study findings provide sufficient significance to foster meaningful patient care improvements.

LEVEL OF EVIDENCE

Systematic review, Level III.

Editorial Commentary: Hamstring Tendon Regeneration After Autograft Harvest

While radiographic and histologic data show features of hamstring tendon regeneration after harvest for ligament reconstruction, we remain skeptical that hamstring regeneration is clinically meaningful. We cannot recommend reharvest for revision surgery.