Biomechanical Analysis of Suture Anchor vs Tenodesis Screw for FHL Transfer

Clinical and biomechanical comparison of suture-external button versus interference screw associated with V-Y advancement or turndown flaps for flexor hallucis longus transfer in chronic Achilles tendon rupture

PURPOSE

Surgical treatment of chronic Achilles tendon rupture is a technically challenging procedure. We aimed to compare the clinical outcomes, range of motion, and strength of ankle plantar- and dorsiflexors between two techniques for fixation of flexor hallucis longus tendon to the calcaneus: interference screw and suture-external button.

METHODS

Twenty-five patients participated in this retrospective comparative study. All patients underwent short harvest FHL tendon transfer for chronic AT rupture were asked for a follow-up visit, at least one year following surgery. The outcomes were evaluated by visual analog scale (VAS), AOFAS ankle-hindfoot score, and VISA-A questionnaire. Ankle ROM with possible restriction in addition to isokinetic strength of ankle plantar- and dorsiflexors was assessed.

RESULTS

No statistically significant difference was observed between the groups for pain (P = 0.81), AOFAS ankle-hindfoot scale (P = 0.97), and VISA-A (P = 0.44). Notably, more decrease in ankle dorsiflexion was seen in interference screw group in comparison with suture-external button group (4.4 ± 6.6 vs. 9.5 ± 6.1 degrees, P = 0.06). The difference of active dorsiflexion between operated and non-operated side in interference screw group was statistically significant (P = 0.02). Biotenodesis screw imposed more limb asymmetry in comparison with suture-external button technique.

CONCLUSIONS

Fixation of transcalcaneal FHL tendon transfer for chronic AT either by interference screw or suture-external button has encouraging postoperative clinical results. Although ROM of the ankle joint reduced in both techniques, interference screw may result in more reduction in dorsiflexion of the ankle.

Does FHL Tendon Transfer Alter the Outcome of Haglund Deformity Treatment by Using Debridement and Ostectomy in Patients Older Than 50 Years? A Single-Blinded Randomized Controlled Trial

Background

Chronic Achilles tendinopathy following Haglund disease is a common ankle condition that is difficult to manage. In this study, we will compare the clinical outcomes of debridement and ostectomy with and without FHL tendon transfer in treating Haglund deformity.

Methods

Forty eligible patients aged >50 years who did not respond to conservative treatment were randomly divided into 2 groups for surgical approach: using flexor hallucis longus (FHL) tendon transfer (FHL group) or "standard procedure" (control group). The main surgical treatment included debridement and ostectomy. AOFAS and VISA-A scores were obtained from all patients pre- and postoperatively.

Results

Twenty patients were assigned to each of the 2 groups and were observed for at least 1 year. The American Orthopaedic Foot & Ankle Society (AOFAS) ankle hindfoot scores and the Victorian Institute of Sports Assessment self-administered Achilles (VISA-A) questionnaires scores improved more in the FHL group; however, the average difference in the change in scores did not reach the levels previously reported for minimal clinically important differences. Surgical complications and hallux function were not significantly different between the 2 groups.

Conclusion

We found that FHL tendon transfer may improve the clinical outcome scores of Achilles tendon treatment in patients aged >50 years using debridement and ostectomy. However, tendon transfer increases the time of surgery and creates additional skin incisions, which may cause more short-term wound complications, and the significance of the differences in outcome improvement may not be clinically meaningful.

Level of Evidence

Level II, grade A recommendation.

Comparison of Staple, Anchor, and Tenodesis Screw for Posterior Tibialis Tendon Fixation: A Biomechanical Analysis

Various posterior tibialis tendon fixation techniques are described in literature. Suture anchor, staple and tenodesis screws are widely used for posterior tibialis tendon transfer, but their stiffness and the maximal ultimate failure load were not tested before. We aimed to compare the initial ultimate failure load and stiffnesses of suture anchor, staple and tenodesis screws on bovine tendon fixation to bovine metaphyseal bone. Thirty-five fresh bovine ankle joints and hooves were obtained from a local abattoir. Metatarsals bones with long extensor tendons were harvested. Staple group had 15, suture anchor group had 10, and tenodesis screw group had 10 samples. All fixations were tested with Instron® ElectroPuls® E10000 Test Instrument. Ultimate failure load and failure location were noted. Staple group's median ultimate failure load was 210.03 N (IQR: 133.43), suture anchor group's was 124.33 N (IQR: 63.67), and tenodesis screw group's was 394.46 N (IQR:115.09). Median stiffness of the staple group was 19.87 N/m (IQR: 15.29); the tenodesis screw group's was 20.28 N/m (IQR: 6.18), the anchor group's was 8.54 N/m (IQR: 4.35). Staples' failure occurred on tendon-staple interface, while suture anchors' occurred on anchor-suture interface and tenodesis screws' occurred on tendon-suture interface. Tenodesis screws' ultimate failure load was the highest (tenodesis vs anchor and staple p < .001 and p = .032, respectively). Staple fixation is less expensive than the other methods and can provide sufficient fixation strength but was weaker than the tenodesis screw fixation. Staples are still a good choice for tendon to bone fixation, whereas the suture anchors provide lower fixation strength at a higher cost.

Achilles Tendon Ruptures and Repair in Athletes-a Review of Sports-Related Achilles Injuries and Return to Play

PURPOSE OF REVIEW

Achilles tendon ruptures (ATR) are detrimental to sports performance, and optimal treatment strategy and guidelines on return to play (RTP) remain controversial. This current review investigates the recent literature surrounding nonoperative versus operative management of ATR, clinical outcomes, and operative techniques to allow the athlete a successful return to their respective sport.

RECENT FINDINGS

The Achilles tendon (AT) is crucial to the athlete, as it is essential for explosive activities such as running and jumping. Athletes that sustain an ATR play in fewer games and perform at a lower level of play compared to age-matched controls. Recent studies also theorize that ATRs occur due to elongation of the tendon with fatigue failure. Biomechanical studies have focused on comparing modes of fixation under dynamic loading to recreate this mechanism. ATRs can be career-ending injuries. Fortunately, the recent incorporation of early weight-bearing and functional rehabilitation programming for non-operative and operative patients alike proves to be beneficial. Especially for those treated nonoperatively, with the incorporation of functional rehabilitation, the risk of re-rupture among non-operative patients is beginning to approach the historical lower risk of re-rupture observed among patients treated operatively. Despite this progress in decreasing risk of re-rupture particularly among non-operative patients, operative managements are associated with unique benefits that may be of particular interest for athletes and active individuals. Recent studies demonstrate that operative intervention improves strength and functional outcomes with more efficacy compared to nonoperative management with rehabilitation. The current literature supports operative intervention in elite athletes to improve performance and shorten the duration to RTP. However, we acknowledge that surgical intervention does have inherent risks. Ultimately, most if not all young and/or high-level athletes with an ATR benefit from surgical repair, but it is crucial to take a stepwise algorithmic approach and consider other factors, which may lead towards nonoperative intervention. These factors include age, chronicity of injury, gap of ATR, social factors, and medical history amongst others in this review.

A Critical Biomechanical Evaluation of Foot and Ankle Soft Tissue Repair

The objective of this article is to review the biomechanical stresses that occur during normal physiologic function of lower extremity soft tissue anatomic structures and to use this as a baseline for a critical analysis of the medical literature because it relates to surgical reconstruction following injury. The Achilles tendon, anterior talofibular ligament, plantar plate, and spring ligament are specifically evaluated.

Systematic review of tendon transfers in the foot and ankle using interference screw fixation: Outcomes and safety of early versus standard postoperative rehabilitation

AIMS

To compare the outcomes of early and standard rehabilitation protocols following tendon transfers in the foot and ankle using interference screw fixation (ISF).

METHODS

A systematic review was performed for relevant articles (1998 to 2020) reporting foot tendon transfer using ISF in adults. The primary outcome was early tendon failure. Secondary outcomes included function and complications.

RESULTS

In total, 21 studies met the inclusion criteria, totalling 494 patients. Seven studies reported early rehabilitation protocols. The rate of early tendon failure was zero for each protocol and studies consistently reported a significant improvement in function. No differences were found comparing different rehabilitation protocols for tendon transfer for Achilles tendon pathology and foot drop.

CONCLUSION

Both early and standard rehabilitation protocols are associated with high patient satisfaction and low complication rates, but currently there is a lack of evidence to support early loaded activities or motion.

LEVEL OF EVIDENCE

IV Systematic review including case series.

Biomechanical Analysis of Single Interference Screw vs Interference Screw With Cortical Button for Flexor Hallucis Longus Transfer

Background:

Flexor hallucis longus tendon transfer (FHL) with a cortical button tension slide is an innovative addition that has not been measured against traditional methods.

Methods:

12 pairs (n=24) of fresh-frozen cadaveric tibia-to-toe samples were used and randomized to receive one of the operative FHL techniques. Specimens underwent bone density analysis. Biomechanical loading was applied between 20 and 60 N at 1 Hz for 100 cycles. Post–cyclic load to failure occurred at 1.25 mm/s. Cyclic displacement, structural stiffness, and ultimate load were derived from load-displacement curves. Student t tests evaluated significant effects between both FHL techniques. Linear regression analysis assessed interactions between bone density and strength of FHL technique.

Results:

Average tendon diameter was 5.44±0.46 mm. Average bone density was 1.06±0.08 g/cm². Addition of a cortical button to FHL transfer did not significantly affect cyclic displacement (0.78±0.52 mm vs 0.87±0.80 mm) or structural stiffness (162.11±43.34 N/mm vs 167.57±49.19 N/mm). Cortical button addition to FHL transfer resulted in significantly increased ultimate load (343.72±68.93 N) compared with interference screw alone (255.62±77.17 N) (P = .0002). Linear regression analyses did not reveal any significant interactions between bone density and FHL tendon transfer technique.

Conclusion:

Enhanced strength can be achieved with FHL tendon transfer to calcaneus using an interference screw and cortical button tension slide technique as compared to an interference screw alone. Cortical buttons in the setting of FHL tendon transfer to the calcaneus offers an additional level of support.

Clinical Relevance:

Operative cases presenting with poor bone quality due to osteoporosis or osteopenia could benefit from cortical button fixation during FHL transfer. Clinical studies are needed to determine if the increased construct stability conferred from the additional use of a flip button results in fewer FHL transfer failures or better clinical outcomes.

Level of Evidence:

Level V, Controlled Laboratory Study.

Bone Staples Provide Favorable Primary Stability in Cortical Fixation of Tendon Grafts for Medial Collateral Ligament Reconstruction: A Biomechanical Study

Background:

The use of the interference screw (IFS) for the cortical fixation of tendon grafts in knee ligament reconstruction may lead to converging tunnels in the multiligament reconstruction setting. It is unknown whether alternative techniques using modern suture anchor (SA) or bone staple (BS) fixation provide sufficient primary stability.

Purpose:

To assess the primary stability of cortical fixation of tendon grafts for medial collateral ligament (MCL) reconstruction using modern SA and BS methods in comparison with IFS fixation.

Study Design:

Controlled laboratory study.

Methods:

Cortical tendon graft fixation was performed in a porcine knee model at the tibial insertion area of the MCL using 3 different techniques: IFS (n = 10), SA (n = 10), and BS (n = 10). Specimens were mounted in a materials testing machine, and cyclic loading for 1000 cycles at up to 100 N was applied to the tendon graft, followed by load-to-failure testing. Statistical analysis was performed using 1-way analysis of variance.

Results:

There were no statistical differences in elongation during cyclic loading or peak failure load during load-to-failure testing between BS (mean ± standard deviation: 3.4 ± 1.0 mm and 376 ± 120 N, respectively) and IFS fixation (3.9 ± 1.2 mm and 313 ± 99.5 N, respectively). SA fixation was found to have significantly more elongation during cyclic loading (6.4 ± 0.9 mm; P < .0001) compared with BS and IFS fixation and lower peak failure load during ultimate failure testing (228 ± 49.0 N; P < .01) compared with BS fixation.

Conclusion:

BS and IFS fixation provided comparable primary stability in the cortical fixation of tendon grafts in MCL reconstruction, whereas a single SA fixation led to increased elongation with physiologic loads. However, load to failure of all 3 fixation techniques exceeded the loads expected to occur in the native MCL.

Clinical Relevance:

The use of BS as a reliable alternative to IFS fixation for peripheral ligament reconstruction in knee surgery can help to avoid the conflict of converging tunnels.

Load to Failure and Stiffness of Interference Screw vs Pulvertaft Weave for Distal Fixation in Peroneal Allograft Reconstruction

BACKGROUND

Allograft reconstruction of the peroneal tendons is an option for treatment of major tears of 1 or both peroneal tendons. No consensus on a superior distal fixation method has been reported. The purpose of the study was to compare load to failure and stiffness of a Pulvertaft weave (PTW) through a residual tendon stump to direct-to-bone interference screw (IS) fixation.

METHODS

Fifteen pairs of long leg cadaver specimens were used. All grafts were secured proximally to the peroneus brevis myotendinous junction via a PTW technique. Distally, the tendons were either sutured to the peroneus brevis stump via PTW or secured to the base of the fifth metatarsal via IS. Stiffness (slope of force/displacement) was measured for the intact tendon and after reconstruction, and finally each specimen was loaded to failure.

RESULTS

Mean load to failure was significantly higher in the PTW group compared with the IS group (373.6 ± 265.5 N vs 150.1 ± 93.1 N; P = .01). The PTW and IS groups had significantly lower stiffness compared with the intact specimens (P < .001). There was no statistical significance in stiffness between the 2 techniques (P = .96).

CONCLUSION

The PTW technique yielded higher load to failure in comparison to IS. There was no difference in overall construct stiffness between both techniques. Both constructs demonstrated 19% decrease in stiffness compared to the intact state.

CLINICAL RELEVANCE

The PTW and IS constructs were biomechanically similar, and these results suggest that both should be moderately overtensioned to compensate for an inherent decreased initial stiffness.

Flexor Hallucis Longus Tendon Single-Incision Transfer Stabilized With Autologous Bone Fixation

Flexor hallucis longus transfer is routinely used as a technique to salvage a chronic or neglected Achilles tendon rupture. The single-incision (or short harvest) technique provides adequate graft suitable for fixation with interference screws. We have used a bore corer instead of a drill to establish the tendon tunnel and at the same time use the harvested autograft for interference fit and avoid the use of screws, providing what we consider to be a more biologic form of fixation.

Flexor digitorum longus tendon transfer to the navicular: tendon-to-tendon repair is stronger compared with interference screw fixation

PURPOSE

To assess whether early rehabilitation could be safe after flexor digitorum longus (FDL) tendon transfer, the current biomechanical study aimed to measure tendon displacement under cyclic loading and load to failure, comparing a traditional tendon-to-tendon (TT) repair with interference screw fixation (ISF).

METHODS

24 fresh-frozen cadaveric below knee specimens underwent FDL tendon transfer. In 12 specimens a TT repair was performed via a navicular bone tunnel. In a further 12 specimens ISF was performed. Using a materials testing machine, the FDL tendon was cycled 1000 times to 150 N and tendon displacement at the insertion site measured. A final load to failure test was then performed. Statistical analysis was performed using two-way ANOVA and an independent t test, with a significance level of p < 0.05.

RESULT

No significant difference in tendon displacement occurred after cyclic loading, with mean tendon displacements of 1.9 ± 1.2 mm (mean ± SD) in the TT group and 1.8 ± 1.5 mm in the ISF group (n.s.). Two early failures occurred in the ISF group, none in the TT group. Mean load to failure was significantly greater following TT repair (459 ± 96 N), compared with ISF (327 ± 76 N), p = 0.002.

CONCLUSION

Minimal tendon displacement of less than 2 mm occurred during cyclic testing in both groups. The two premature failures and significantly reduced load to failure observed in the ISF group, however, indicate that the traditional TT technique is more robust. Regarding clinical relevance, this study suggests that early active range of motion and protected weight bearing may be safe following FDL tendon transfer for stage 2 tibialis posterior tendon dysfunction.

Flexor hallucis longus tendon transfer for chronic Achilles tendon rupture. A retrospective study

BACKGROUND

The transfer of Flexor Hallucis Longus Tendon (FHL) is an established method for the treatment of chronic Achilles tendon ruptures. An extensive examination of power, strength, endurance and complications related to this procedure is presented.

METHODS

21 patients treated with open FHL transfer for chronic Achilles tendon rupture were studied retrospectively. Medical records were reviewed. The patients were examined with a test battery for triceps surae strength, functional tests and PROMs.

RESULTS

The median maximal concentric strength was equal,1300 vs 1336W, comparing affected with unaffected side. The endurance tests showed a larger difference, 219J vs. 2398J, respectively. The median AOFAS score was 87. 11 of 21 patients sustained one or more complications; the most common were infection, disturbed wound healing, and clawing of small toes.

CONCLUSIONS

Patients achieve almost normal maximal strength after open FHL transfer, but endurance is notably lower. The complication rate was high.

Flexor Hallucis Longus Transfer Improves Achilles Tendon Load to Failure in Surgery for Non-Insertional Tendinopathy: A Biomechanical Study

BACKGROUND

Non-insertional Achilles tendinopathy is a common disorder that may be treated with surgical debridement. A flexor hallucis longus (FHL) transfer is recommended if debridement of ≥50% is performed; however, there are no biomechanical data to support this. The purpose of this study was to assess the added biomechanical strength provided by an FHL transfer with incrementally sized non-insertional Achilles tendon defects.

METHODS

Thirty matched-pair below-the-knee cadaveric specimens (n = 60) (mean age at the time of donor death, 67 years; range, 36 to 74 years) were obtained and randomly divided into 3 groups according to whether the defect was 25%, 50%, or 75% of the tendon width. One specimen of each pair was then randomly selected to undergo FHL transfer using interference screw fixation. All specimens then underwent cyclic loading of 100 N, and elongation of the medial and lateral limbs of the tendon defect was recorded. The constructs were then loaded to failure to measure stiffness, ultimate strength, and peak elongation before failure.

RESULTS

The specimens with a 75% defect had significantly less elongation of the medial and lateral tendon-defect limbs when an FHL transfer had been done (p < 0.05). Ultimate load to failure was significantly increased in all groups (by 242 to 270 N depending on the defect size) following FHL transfer. Failures usually occurred through the tendon defect in the 75% and 50% defect groups, whereas all failures occurred at the Achilles tendon insertion when a 25% defect had been created. No significant differences were found in peak elongation with the addition of an FHL transfer. FHL augmentation resulted in significantly greater stiffness in the 25% and 75% defect groups (p < 0.05).

CONCLUSIONS

This study showed that an FHL transfer significantly increased load to failure of Achilles tendons with a non-insertional defect involving 25%, 50%, and 75% of the tendon width. The mechanism of failure was usually through the defect in the specimens with a 50% or 75% defect, supporting the use of FHL augmentation with debridement of ≥50%.

CLINICAL RELEVANCE

The present study supports the mechanical concept that FHL transfer is indicated when debridement of the Achilles tendon is ≥50%.

Biomechanical Comparison of Suture-External Button Fixation vs Internal Suspension Fixation for Tendon Transfers of the Feet

BACKGROUND

Fixation of tendon transfers in pediatric feet typically involves passing a suture that is secured to a tendon, through an intraosseous tunnel, and tying it over an external button on the plantar foot, with appropriate tension. After adequate time is allowed for bone-tendon healing, the suture and button are removed. This construct can be complicated by suture breakage with loss of fixation, and/or skin ulceration under the button. Internal suspension systems of tendons and ligaments in adults have demonstrated excellent fixation strength and minimal intraosseous tunnel displacement, with no risk of skin ulceration and no need for suture and button removal. This study compared the biomechanical properties of the suture-external button and internal suspension fixation techniques in cadavers. The primary outcome and secondary outcomes were displacement of suture-fixation construct during dynamic loading, and static loading, respectively.

METHODS

Nine adult cadaver feet were obtained. Both the external button and internal suspension techniques were tested once in each cadaver, in random order. Relative displacement of the fixation construct within the bone tunnel was recorded with video capture during dynamic and static loading. A custom Matlab script processed video and materials testing data. Static and cyclic displacements were analyzed between fixation groups using a paired t test (alpha value =0.05).

RESULTS

Internal suspension fixation had significantly less mean displacement of the tendon within the bone tunnel than the external button technique during dynamic (0.3 mm internal suspension system, 0.7 mm external button, P = .0115) and static loading (0.4 mm internal suspension system, 2.2 mm external button, P = .0019).

CONCLUSIONS

Internal suspension systems may provide superior fixation compared to the traditional external button for tendon transfers, with the added benefit of avoiding the risk of skin ulceration and the need for suture and button removal.

CLINICAL RELEVANCE

It appears internal suspension method of tendon transfer fixation would be an acceptable alternative to traditional methods of fixation with an external button.

Achilles Tendinopathy and Associated Disorders

Degenerative disorders of the Achilles tendon are common, affecting up to 18% of the adult population. A thorough evaluation including a focused history, physical examination, and diagnostic studies helps in choosing the appropriate treatment. Initial treatment is usually nonoperative, consisting of activity modification, bracing, and physical therapy. Patents who fail nonoperative management may be treated operatively with a wide range of procedures from endoscopic surgery to open debridement and tendon transfer. Understanding a patient’s expectations and educating patients about potential treatments and their outcomes enables informed collaborative decision making. This article will review the evaluation and management Achilles tendinopathy and associated disorders.

Endoscopic Transfer of Flexor Hallucis Longus Tendon for Chronic Achilles Tendon Rupture: Technical Aspects and Short-Time Experiences

BACKGROUND

Chronic Achilles tendon ruptures can lead to reduced power of plantar flexion in the ankle with impaired gait ability. The open 1- or 2-incision technique for flexor hallucis longus transfer has proven good functional outcome but has the disadvantage of relatively extensive surgery performed at a vulnerable location. To reduce the risk of soft tissue problems, the flexor hallucis longus transfer can be performed endoscopically.

MATERIAL AND METHOD

An endoscopic technique for flexor hallucis longus transfer is presented together with the experiences from the first six patients operated with this method.

RESULTS

No wound healing problems or infections. Five of 6 patients managed single leg heel raise on the affected side 12 months after surgery.

CONCLUSION

The functional results are promising. The soft tissue dissection is minor, and no patients had postoperative wound healing problems or infection. Endoscopic flexor hallucis longus transfer may be an operative procedure that can be considered also in patients with potential wound healing problems.

LEVELS OF EVIDENCE

Level IV: Technical note/case series without controls.

Biomechanical evaluation of two methods of fixation of a flexor hallucis longus tendon graft

Aims

The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing.

Materials and Methods

Tendon grafts were undertaken in 24 paired lower-leg specimens and randomly assigned in two groups using fixation with a transosseus suture (suture group) or a tenodesis screw (screw group). The biomechanical behaviour was evaluated using cyclical and ultimate loading tests. The Student’s t-test was performed to assess statistically significant differences in bone mineral density (BMD), displacement, the slope of the load-displacement curves, and load to failure.

Results

The screw group showed less displacement (loosening) during cyclical loading, which was significant during 300, 500, 600, 700, 800, 900, and 1000 cycles (p < 0.05: other cycles: 0.079 < p < 0.402). Compared with the suture group, the screw group had higher mean ultimate load values (133.6 N, sd 73.5 vs 110.1 N, sd 46.2; p = 0.416).

Conclusion

Fixation of the FHL tendon with a tenodesis screw enables a less invasive procedure to be undertaken and shows similar biomechanical behaviour and primary strength compared with fixation using a transosseus suture. Cite this article: Bone Joint J 2018;100-B:1175–81.

Strength of Interference Screw Fixation to Cuboid vs Pulvertaft Weave to Peroneus Brevis for Tibialis Posterior Tendon Transfer for Foot Drop

BACKGROUND

Tibialis posterior (TP) tendon transfer is an effective treatment for foot drop. Currently, standard practice is to immobilize the ankle in a cast for 6 weeks nonweightbearing, risking postoperative stiffness. To assess whether early active dorsiflexion and protected weightbearing could be safe, the current study assessed tendon displacement under cyclic loading and load to failure, comparing the Pulvertaft weave (PW) to interference screw fixation (ISF) in a cadaveric foot model.

METHODS

Twenty-four cadaveric ankles had TP tendon transfer performed, 12 with the PW technique and 12 with ISF to the cuboid. The TP tendon was cycled 1000 times at 50 to 150 N and then loaded to failure in a materials testing machine. Tendon displacement at the insertion site was recorded every 100 cycles. An independent t test and 2-way analysis of variance were performed to compare techniques, with a significance level of P < .05.

RESULTS

Mean tendon displacement was similar in the PW group (2.9 ± 2.5 mm [mean ± SD]) compared with the ISF group (2.4 ± 1.1 mm), P = .35. One specimen in the ISF group failed early by tendon pullout. None of the PW group failed early, although displacement of 8.9 mm was observed in 1 specimen. Mean load to failure was 419.1 ± 82.6 N in the PW group in comparison to 499.4 ± 109.6 N in the ISF group, P = .06.

CONCLUSION

For TP tendon transfer, ISF and PW techniques were comparable, with no differences in tendon displacement after cyclical loading or load to failure. Greater variability was observed in the PW group, suggesting it may be a less reliable technique.

CLINICAL RELEVANCE

The results indicate that early active dorsiflexion and protected weightbearing may be safe for clinical evaluation, with potential benefits for the patient compared with cast immobilization.

Outcomes After Primary Repair of Insertional Ruptures of the Achilles Tendon

BACKGROUND

Achilles tendon insertional sleeve avulsions occur when the Achilles distal tendon sleeve ruptures off of its insertion into the calcaneal tuberosity, sometimes with a small bony fragment from calcific tendinosis. Little evidence exists describing the outcomes and rerupture rate after operative management of Achilles tendon sleeve avulsions.

METHODS

A retrospective chart review was performed to identify patients who sustained an Achilles sleeve avulsion injury treated with operative repair between October 2005 and July 2014. A cohort of 16 patients from the general population and 12 professional athletes were included in the study. The primary outcome variable was rerupture of the Achilles tendon or need for revision surgery. Secondary outcome variables included the Coughlin Satisfaction Scale, visual VR-12, and Foot and Ankle Ability Measure (FAAM).

RESULTS

In the general population cohort, median follow-up was 8.1 years (range, 3.2-11.1 years). The median FAAM Activities of Daily Living score was 100 (range, 42.9-106), and the median FAAM Sports score was 100 (range, 7.1-103.6). The median VR-12 Mental Component Score was 66.9 (range, 45.6-71.8), and the median VR-12 Physical Component Score was 53 (range, 30.8-57.5). In the cohort of professional athletes, preceding insertional Achilles symptoms were present in 91.7% (11/12) of athletes for more than 9 months prior to rupture. All athletes returned to play with an average time of 13.4 months. No patients sustained a rerupture in the follow-up period.

CONCLUSION

Operative repair of Achilles tendon sleeve avulsions was safe and effective with high patient satisfaction and good clinical outcomes in patients from the general population.

LEVEL OF EVIDENCE

Level IV, retrospective case series.