Tendon end separation with loading in an Achilles tendon repair model: comparison of non-absorbable vs. absorbable sutures

The option of transosseous distal suture placement during minimally invasive Achilles tendon repair for high-risk patients can improve outcomes, however does not prevent re-rupture

PURPOSE

Achilles tendon ruptures (ATRs) close to the insertion, in high-level athletes, and in patients at high risk of re-rupture, may be better suited to operative repair. Minimally Invasive Repair (MIR) of the Achilles tendon has excellent outcome and low complication rates. Traditionally MIR has showed lower repair strength, failing due to suture pull-out from the distal tendon stump. The aim of this study was to describe the outcome of ATR patients who received transosseous distal suture placement using a standard technique as a reference.

METHODS

Following ATR, patients were evaluated for pre-injury activity level, body weight, location of the tear and size of the distal Achilles tendon stump. Patients considered to be at high-risk of re-rupture: Tegner level ≥ 8, body weight ≥ 105Kg and distal ATR, received transosseous (TO) distal suture placement (n = 20) rather than the usual transtendinous (TT) technique (n = 55). Patient reported outcome measures and functional evaluation was performed at 12 months following repair.

RESULTS

At 12 months follow up both methods resulted in good median (IQR) Achilles tendon Total Rupture Score TO 83.8 (74-88.3) vs. TT 90 (79-94), low increased relative Achilles Tendon Resting Angle TO -3.5˚ (3.6) vs. TT -3.5˚ (3.3) and mean (SD) Single leg Heel-Rise Height Index TO 88.2% (9.9) vs. TT 85.6% (9.9) (n.s.). There were 4 re-ruptures in the high-risk group and 2 in the group receiving TT distal suture placement. All but one of these were traumatic in nature. The mode of failure following TO distal suture placement was proximal suture pull out.

CONCLUSIONS

To distal suture placement during minimally-invasive Achilles tendon repair for higher-risk patients can lead to results equivalent to those in lower-risk patients treated with a standard TT MIR technique, except for the re-rupture rate which remained higher. There may be factors that have greater influence on outcome other than suture placement following ATR.

Biomechanical Comparison of Four- versus Six-Strand Transosseous Suture Repair for Patellar Tendon Rupture

BACKGROUND

 Surgical repair is indicated for patellar tendon ruptures that result in loss of knee extensor mechanism function. However, biomechanical studies report conflicting results when comparing transosseous suture versus suture anchor repair techniques. This discrepancy may be due to inconsistencies in experimental design as these studies use various numbers of suture strands. Therefore, the main objective of this study is to compare the ultimate load of four- versus six-strand transosseous suture repair. Secondary objectives are to compare gap formation after cyclical loading and mode of failure.

METHODS

 Six pairs of fresh-frozen cadaveric specimen were randomly allocated to either four- or six-strand transosseous suture repair. Specimen underwent preconditioning cyclical loading and then load to failure.

RESULTS

 The six-strand repair had a significantly higher maximum load to failure compared with the four-strand repair (mean difference = 319.3 N [57.9%], p = 0.03). There was no significant difference in gap length after cyclical loading or at max load. There were no significant differences in mode of failure.

CONCLUSION

 Utilizing a six-stand transosseous patella tendon repair construct with one additional suture increases overall construct strength by over 50% compared with a four-strand construct.

Gouty Tophi Encompassing Retained Suture Material 7 Years After Achilles Tendon Rupture Repair

CASE

We report the case of a 32-year-old male patient with no history of gout who developed gouty tophi encompassing retained suture material 7 years after initial repair of a ruptured Achilles tendon. The patient had a posterior ankle mass concerning for abscess. Monosodium urate crystals were identified, and uric acid level was elevated at the time of irrigation and debridement.

CONCLUSION

Surgical site gout is a rare but important phenomenon to recognize in the treatment of patients with Achilles tendon repairs, particularly in patients with a history of abscess, infection, or collections localized to retained suture material.

Absorbable versus nonabsorbable sutures for the Krackow suture repair of acute Achilles tendon rupture: a prospective randomized controlled trial

AIMS

Although absorbable sutures for the repair of acute Achilles tendon rupture (ATR) have been attracting attention, the rationale for their use remains insufficient. This study prospectively compared the outcomes of absorbable and nonabsorbable sutures for the repair of acute ATR.

METHODS

A total of 40 patients were randomly assigned to either braided absorbable polyglactin suture or braided nonabsorbable polyethylene terephthalate suture groups. ATR was then repaired using the Krackow suture method. At three and six months after surgery, the isokinetic muscle strength of ankle plantar flexion was measured using a computer-based Cybex dynamometer. At six and 12 months after surgery, patient-reported outcomes were measured using the Achilles tendon Total Rupture Score (ATRS), visual analogue scale for pain (VAS pain), and EuroQoL five-dimension health questionnaire (EQ-5D).

RESULTS

Overall, 37 patients completed 12 months of follow-up. No difference was observed between the two groups in terms of isokinetic plantar flexion strength, ATRS, VAS pain, or EQ-5D. No re-rupture was observed in either group.

CONCLUSION

The use of absorbable sutures for the repair of acute ATR was not inferior to that of nonabsorbable sutures. This finding suggests that absorbable sutures can be considered for the repair of acute ATRs. Cite this article: Bone Joint J 2022;104-B(8):938-945.

Biomechanical comparisons of three minimally invasive Achilles tendon percutaneous repair suture techniques

BACKGROUND

While no gold standard exists for the management of Achilles tendon ruptures, surgical repair is common in healthy and active patients. Minimally invasive repair methods have become increasingly popular, while biomechanical equivalency hasn't been proven yet.

METHODS

A mid-substance Achilles tendon rupture was created 6 cm proximal to the calcaneal insertion in 27 fresh-frozen cadaveric ankles. Specimens were randomly allocated to 1 of 3 repair techniques: Huttunen et al. (2014) (1) PARS Achilles Jig System, Nyyssönen et al. (2008) (2) Achilles Midsubstance SpeedBridge™, Schipper and Cohen (2017) (3) Dresdner Instrument and subsequently subjected to cyclic loading with 250 cycles each at 1 Hz with 4 different loading ranges (20-100 N, 20-200 N, 20-300 N, and 20-400 N).

FINDINGS

After 250 cycles no significant differences in elongation were observed between PARS and Dresdner Instrument(p = 1.0). Furthermore, SpeedBridge™ repairs elongated less than either Dresdner Instrument (p = 0.0006) or PARS (p = 0.102). Main elongation (85%) occurred within the first 10 cycles with a comparable elongation in between 10 and 100 and 100-250 cycles. While all repairs withstood the first 250 cycles of cyclic loading from 20 to 100 N, only the PARS (468 ± 175) and Midsubstance SpeedBridge™ (538 ± 208) survived more cycles. Within all 3 groups suture cut out was seen to be the most common failure mechanism.

INTERPRETATION

Within all groups early repair elongation was seen. While this was least obvious within the SpeedBridge™ technique, ultimate strengths of repairs (cycles to failure) were comparable across PARS and SpeedBridge™ with a decline in the Dresdner Instrument group.

Ultimate Load Measuring System for Fixation of Soft Tissue to Bone

BACKGROUND

The initial ultimate load for graft fixation is one of the essential factors in the reconstruction of lateral ankle ligaments. Several anchoring devices have been developed to fix the substitute ligament into the bone. A fair comparison of these fixation methods warrant a reproducible examination system. The purpose of this study was to make an experimental animal model and to compare the initial ultimate loads of 3 graft fixation methods, including the use of EndoButton (EB), interference screw (IFS), and a novel socket anchoring (SA) technique.

METHODS

Porcine calcaneus bones and 5-mm-wide split bovine Achilles tendons were used as fixation bases and graft materials, respectively. Both ends were firmly sutured side-by-side, using the circumferential ligation technique as a double-strand substitute that was 45 mm in length. Porcine calcanei with similar characteristics to adult human calcanei were mounted on a tensile testing machine, and substitutes were fixed into bones using the 3 fixation methods. A polyester tape was passed through the tendon loop and connected to a crosshead jig of the testing machine. The initial ultimate loads were measured in 15 specimens for each fixation method to simulate a lateral ankle ligament (LAL) injury.

RESULTS

The ultimate loads (ULs) were 223.6 ± 52.7 N for EB, 229.7 ± 39.7 N for SA, and 208.8 ± 65.3 N for IFS. No statistically significant difference was observed among the 3 groups (P = .571). All failures occurred at the bone-ligament substitute interface.

CONCLUSION

The initial ULs in all 3 fixation methods were sufficient for clinical usage. These values were larger than the UL of the anterior talofibular ligament; however, these were smaller than the UL of the calcaneofibular ligament.

CLINICAL RELEVANCE

In an experimental animal model, ULs for SA, EB, and IFS techniques showed no significant difference. All failures were observed in the fixation site of the calcaneus and were overwhelmingly related to suture fixation failure.

What Is the Best Evidence to Guide Management of Acute Achilles Tendon Ruptures? A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Uncertainty exists regarding the best treatment for acute Achilles tendon ruptures. Simultaneous comparison of the multiple treatment options using traditional study designs is problematic; multiarm clinical trials often are logistically constrained to small sample sizes, and traditional meta-analyses are limited to comparisons of only two treatments that have been compared in head-to-head trials. Network meta-analyses allow for simultaneous comparison of all existing treatments utilizing both direct (head-to-head comparison) and indirect (not previously compared head-to-head) evidence.

QUESTIONS/PURPOSES

We performed a network meta-analysis of randomized controlled trials (RCTs) to answer the following questions: Considering open repair, minimally invasive surgery (MIS) repair, functional rehabilitation, or primary immobilization for acute Achilles tendon ruptures, (1) which intervention is associated with the lowest risk of rerupture? (2) Which intervention is associated with the lowest risk of complications resulting in surgery?

METHODS

This study was conducted with methods guided by the Cochrane Handbook for Systematic Reviews of Interventions and is reported in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension statement for incorporating network meta-analysis. Five databases and grey literature sources (such as major orthopaedic meeting presentation lists) were searched from inception to September 30, 2019. Included studies were RCTs comparing treatment of acute Achilles tendon ruptures using two or more of the following interventions: primary immobilization, functional rehabilitation, open surgical repair, or MIS repair. We excluded studies enrolling patients with chronic ruptures, reruptures, and preexisting Achilles tendinopathy as well as studies with more than 20% loss to follow-up or less than 6 months of follow-up. Nineteen RCTs (1316 patients) were included in the final analysis. The mean number of patients per study treatment arm was 35 ± 16, mean age was 41 ± 5 years, mean sex composition was 80% ± 10% males, and mean follow-up was 22 ± 12 months. The four treatment groups were compared for the main outcomes of rerupture and complications resulting in operation. The analysis was conducted using random-effects Bayesian network meta-analysis with vague priors. Evidence quality was evaluated using Grades of Recommendation, Assessment, Development, and Evaluation methodology. We found risk of selection, attrition, and reporting bias to be low across treatments, and we found the risk of performance and detection bias to be high. Overall risk of bias between treatments appeared similar.

RESULTS

We found that treatment with primary immobilization had a greater risk of rerupture than open surgery (odds ratio 4.06 [95% credible interval {CrI} 1.47 to 11.88]; p < 0.05). There were no other differences between treatments for risk of rerupture. Minimally invasive surgery was ranked first for fewest complications resulting in surgery and was associated with a lower risk of complications resulting in surgery than functional rehabilitation (OR 0.16 [95% CrI 0.02 to 0.90]; p < 0.05), open surgery (OR 0.22 [95% CrI 0.04 to 0.93]; p < 0.05), and primary immobilization (OR < 0.01 [95% CrI < 0.01 to 0.01]; p < 0.05). Risk of complications resulting in surgery was no different between primary immobilization and open surgery (OR 1.46 [95% CrI 0.35 to 5.36]). Data for patient-reported outcome scores and return to activity were inappropriate for pooling secondary to considerable clinical heterogeneity and imprecision associated with small sample sizes.

CONCLUSION

Faced with acute Achilles tendon rupture, patients should be counseled that, based on the best-available evidence, the risk of rerupture likely is no different across contemporary treatments. Considering the possibly lower risk of complications resulting in surgery associated with MIS repair, patients and surgeons must balance any benefit with the potential risks of MIS techniques. As treatments continue to evolve, consistent reporting of validated patient-reported outcome measures is critically important to facilitate analysis with existing RCT evidence. Infrequent but serious complications such as rerupture and deep infection should be further explored to determine whether meaningful differences exist in specific patient populations.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Prospective randomized clinical trial of open operative, minimally invasive and conservative treatments of acute Achilles tendon tear

INTRODUCTION

The acute Achilles tendon rupture (AATR) is a common injury of great importance in an increasingly active society. When early functional treatment is established, recent literature shows comparable rates of re-rupture in conservative and surgical treatments of AATR. However, there is no study comparing the outcome using a dynamometer. The aim of this study is to evaluate the results of patients with AATR treated conservatively and surgically using a dynamometer. In addition, the data are compared to evaluation of the Achilles tendon with ultrasound.

MATERIALS AND METHODS

Between 2012 and 2015, 90 patients (mean age 41 years, male-to-female ratio 81:9) with AATR were enrolled in a prospective, randomized, and monocentric study. Thirty patients were assigned to each of the three different treatment groups. Group OPEN received a conventional open suture of the Achilles tendon, group MIN received a minimally invasive suture and patients in group CONS were treated conservatively. Follow-up treatment was the same for all patients regardless of the group they were assigned to. Plantar flexion force was assessed using a dynamometer (Biodex® System 3 Pro, Biodex Medical Systems). Further evaluation included a physical test and ultrasound of the Achilles tendon.

RESULTS

Sixty-nine patients were available for a 24-month follow-up. In each of the OPEN and MIN groups, there was one re-rupture. In the CONS group, there were two re-ruptures. A positive correlation between the Biodex® dynamometer measurement and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS-AH) could be found in all groups. Nevertheless, there were no significant differences between the treatment groups after 2 years. On sonography, all patients showed isolated structure loosening and a significantly thickened cross-sectional area compared with the non-injured opposite side, without differences between the groups. There was no correlation between the Biodex® measurement and sonographic outcome.

CONCLUSION

At 24-month follow-up, no significant difference can be found in patients with AATR treated operatively or conservatively. It is, therefore, important to inform patients with AATR regarding the respective advantages and disadvantages of the individual treatment strategies.

LEVEL OF EVIDENCE

Randomized controlled trial; level 1.

Treatment of a Neglected Patellar Tendon Rupture with a Modified Surgical Technique: Ipsilateral Semitendinosus Autograft Reconstruction with Suture Tape Augmentation

Patellar tendon ruptures are rare, but debilitating injuries are typically seen in young active males in the third and fourth decades of life. They can occur as a single acute injury or from repetitive microtrauma weakening the tendon. Patients typically present complaining of knee pain, swelling, and an inability to perform a straight leg raise. Most conventionally, these injuries are classified as acute (less than two weeks) or chronic (greater than two weeks) based upon the timing of presentation. In patients with patellar tendon ruptures and inability to perform a straight leg raise, patellar tendon repair is most often recommended. A subset of patients with chronic patellar tendon ruptures, however, presents several months after their initial injuries. These neglected patella tendon ruptures present a particularly challenging clinical scenario in which primary repair is often difficult or not possible. This case report describes a modification to an existing surgical technique for reconstructing the patellar tendon using an ipsilateral semitendinosus tendon autograft with suture tape augmentation.