A systematic review of early rehabilitation methods following a rupture of the Achilles tendon

The Effectiveness of the Modified Side-Locking Loop Suture Technique with Early Accelerated Rehabilitation for Acute Achilles Tendon Rupture in Athletes

Background/Objectives: An early accelerated rehabilitation is generally recommended after surgery for acute Achilles tendon ruptures (ATRs). The modified side-locking loop suture (MSLLS) is a surgical technique that provides high tensile strength to the repaired Achilles tendon and allows for a safe, early accelerated rehabilitation protocol without requiring postoperative immobilization. However, there are no reports investigating the clinical outcomes of the MSLLS technique with early accelerated rehabilitation for ATRs. To clarify the effectiveness of the MSLLS technique with an early accelerated rehabilitation protocol for ATR in athletes. Methods: We retrospectively analyzed 27 athletes (Tegner activity score ≥ 6) who underwent surgical treatment using the MSLLS technique for ATR between April 2017 and August 2022. All patients underwent an early accelerated rehabilitation protocol without immobilization. Outcome measures included the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) score taken preoperatively and one year postoperatively, the time required to perform 20 continuous double-leg heel raises (DHR) and single-leg heel raises (SHR), the time to return to the original sport, and the presence of any complications. Results: The mean AOFAS score significantly improved from 37.2 ± 9.7 preoperatively to 96.3 ± 5.3 one year postoperatively. The mean time to be able to perform 20 continuous DHR and SHR was 7.7 ± 1.2 weeks and 11.3 ± 1.6 weeks, respectively. All patients were able to return to their original sport at their pre-injury level in an average of 22.7 ± 3.7 weeks without complication. Conclusions: The MSLLS technique in conjunction with an early accelerated rehabilitation protocol for ATR in athletes produced satisfactory results, with all patients able to return to their original sport at their preinjury level without complication.

Methods of Immobilization after Achilles Tendon Rupture Repair: A Comparative Study in Rat Model

OBJECTIVE

The Achilles tendon (AT) is the most frequently ruptured in the human body. Literature describing different immobilization methods' impact on tendon healing after AT repair is lacking. We compare plaster cast, splint, and K-wire to determine which is the most stable and has the fewest complications.

METHODS

Sixty rats aged 5-6 months were selected to establish Achilles tendon injury in two hind legs model. After suturing the ends of the AT together with a modified "Kessler" method (Prolene 5-0). The skin incision was interrupted and sutured with 1-0 thread. Rats were divided into three immobilization methods (plaster cast group, splint group, and K-wire group). In plaster cast group, the hind leg was cast with plaster in the extended position of the hip and knee joints, and the ankle joint was at 150°. Splint and K-wire group used splints and 0.8-mm K-wires, separately. The fixed period was 4 weeks. The incidence of stability and complications (death, necrosis of the legs, necrosis of the skin, and incisional infection) were recorded. Differences were detected using the chi-square test.

RESULTS

Within 4 weeks observation, K-wires showed better stability (90%) compared with the other two ways (40% in plaster cast group, 65% in splint group; p < 0.05). Rats immobilized with K-wires (10%) suffered significantly lower complications compared with plaster cast and splint group (15%; p < 0.05).

CONCLUSION

K-wire has better stability, lower complication rate than other methods. Immobilization with K-wire may be a promising tool in future clinical Achilles tendon rupture applications.

Fast Functional Rehabilitation Protocol versus Plaster Cast Immobilization Protocol after Achilles Tendon Tenorrhaphy: Is It Different? Clinical, Ultrasonographic, and Elastographic Comparison

BACKGROUND

the incidence of Achilles tendon (AT) rupture is rising; however, there is no clear consensus regarding the optimal treatment. The aim of this retrospective study was to compare instrumental and patient-reported outcome scores after fast functional rehabilitation (group A) versus plaster cast immobilization (group B) programs in patients who underwent AT tenorrhaphy.

METHODS

33 patients, with similar clinical and demographic features, underwent open AT tenorrhaphy between January and July 2018. Of these, 15 patients were treated with fast functional rehabilitation program (group A), and 18 patients were treated with plaster cast immobilization protocol (group B). Sural triceps hypotrophy and functional scores (American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score, and Achilles tendon Total Rupture Score (ATRS)) were recorded at a 12-month follow-up. Ultrasonography (US) and elastosonography (ES) were used to compare the characteristics of the tendons after surgery.

RESULTS

At 12 months, no significant differences in any of the patient-reported outcomes or the instrumental measurement tests were seen between the two groups.

CONCLUSIONS

fast functional rehabilitation after AT surgical repair is safe, effective, and may be the first choice of treatment, especially in young, collaborative, and active patients.

Immediate Weightbearing and Ankle Motion Exercise After Acute Achilles Tendon Rupture Repair

The incidence of Achilles tendon rupture is increasing. Postoperative rehabilitation after repairing acute Achilles tendon rupture is very important because the choice of treatment during the rehabilitation period can influence the results. Moreover, the method of functional rehabilitation varies and is developing steadily. Recent studies recommend a functional rehabilitation protocol, and this approach is accepted widely. This study aimed to introduce our most accelerated functional rehabilitation protocol following surgery for acute Achilles tendon rupture and to review the results retrospectively. From July 2014 to July 2016, 67 patients underwent surgery for acute Achilles tendon rupture by one surgeon. Age, sex, body mass index, injury mechanism, rehabilitation method and progress, time to return to previous physical activity, and complications were evaluated. The mean time to be able to squat fully was 10 ± 4.7 (4-20) weeks. Full squatting was possible in 92.8% (52 patients). The mean time to perform a single-limb heel rise and repetitive single-limb heel rise was 12.6 ± 3.9 (6-24) and 23.3 ± 7.7 (8-40) weeks, respectively. The mean time to return to sports was 20.6 ± 5.2 (12-32) weeks. The major complication rate was 3.5% (one re-rupture and one tendon elongation). The mean pre- and postoperative Achilles Tendon Total Rupture Score was 29.5 ± 3.7 (20-38) and 79.3 ± 18.5 (20-98) points, respectively. The increase was significant (p < .01). In conclusion, immediate full weightbearing and ankle motion exercise after repair of acute Achilles tendon rupture can provide a good rehabilitation option with a low re-rupture rate and satisfactory functional results.

Jigless knotless internal brace versus other open Achilles tendon repairs using a progressive rehabilitation protocol: a biomechanical study

BACKGROUND

The jigless knotless internal brace surgery (JKIB), a modified minimal invasive surgery (MIS) for acute Achilles tendon injury, has advantages of preventing sural-nerve injury in MIS and superficial wound infection in open surgery, as demonstrated in previous clinical research. However, to date, biomechanical testing has not yet been validated.

MATERIALS AND METHODS

Sixty fresh porcine Achilles tendons were used to compare the JKIB with other open surgery techniques, the four-stranded Krackow suture (4sK) and the triple-bundle suture (TBS) in biomechanical testing with cyclic loading set at 1 Hz. This approach simulated a progressive rehabilitation protocol where 20-100 N was applied in the first 1000 cycles, followed by 20-190 N in the second 1000 cycles, and then 20-369 N in the third 1000 cycles. The cycles leading to repair gaps of 2 mm, 5 mm, and 10 mm were recorded. The survival cycles were defined as repair gap of 10 mm.

RESULTS

With respect to survival cycles, a significant difference was found among the three groups, in which the TBS was the most robust, followed by the JKIB and the 4sK, where the mean survived cycles were 2639.3 +/- 263.55, 2073.6 +/- 319.92, and 1425.25 +/- 268.96, respectively. Significant differences were verified via a post hoc analysis with the Mann-Whitney U test after the Bonferroni correction (p < 0.017).

CONCLUSIONS

The TBS was the strongest suture structure in acute Achilles tendon repair. However, the JKIB could be an option in acute Achilles tendon repair with the MIS technique due to it being more robust than the 4sK, which has been typically favored for use in open repair.

The Influence of Early Weightearing, Controlled Motion, and Timing of Orthosis Removal on the Nonoperative Management of Achilles Tendon Rupture: A Systematic Review

This is a systematic review of the non-operative treatment for Achilles tendon rupture aimed at assessing the effect of early weightbearing, controlled motion and orthosis removal on 5 outcome measures. The literature was searched for relevant RCTs and prospective cohort studies. The primary outcome measure was the re-rupture rate. The secondary outcome measures were the rates for DVT, duration before return to work (RTW), return to sports (RTS) and the mean Achilles Tendon Rupture Score (ATRS). Eighteen publications reporting a total of 1068 patients were reviewed. The pooled rates were: re-rupture: 7.3%, DVT: 5.5%, RTW: 10.3 weeks, RTS: 47.7% and ATRS: 78.7. Early compared to late weightbearing was associated with significantly lower rates of DVT, RTW and ATRS but no difference in the rates of re-rupture and RTS. Early controlled motion compared to no motion was associated with significantly lower rates of re-rupture, RTW and ATRS but no difference in the rates of DVT and RTS. Early compared to late orthosis removal was associated with significantly higher rates of re-rupture and ATRS as well as a lower rate of RTW but no difference in the rates of DVT and RTS. The findings relating to re-rupture, DVT, RTW and RTS support the adoption of early weightbearing and controlled motion in the non-operative treatment for Achilles tendon rupture. Early removal of orthosis is not advisable due to an increased risk of re-rupture. The ATRS results were considered inconclusive probably due to inconsistencies in the reporting or heterogeneity in the study population.

Plaster cast versus functional bracing for Achilles tendon rupture: the UKSTAR RCT

BACKGROUND

Achilles tendon rupture affects > 11,000 people each year in the UK, leading to prolonged periods away from work, sports and social activities. Traditionally, the ruptured tendon is held still in a plaster cast for ≥ 8 weeks. Functional bracing is an alternative treatment that allows patients to mobilise earlier, but there is little evidence about how bracing affects patients' recovery.

OBJECTIVES

To measure the Achilles Tendon Rupture Score, quality of life, complications and resource use of patients receiving non-operative treatment for an Achilles tendon rupture treated with plaster cast compared with those treated with functional bracing.

DESIGN

This was a multicentre, randomised, pragmatic, two-group superiority trial.

SETTING

The setting was 39 NHS hospitals.

PARTICIPANTS

A total of 540 adult patients treated non-operatively for Achilles tendon rupture were randomised from July 2016 to May 2018. Exclusion criteria included presenting after 14 days, having had previous rupture and being unable to complete questionnaires.

INTERVENTIONS

A total of 266 participants had a plaster cast applied, with their toes initially pointing to the floor. The cast was changed over 8 weeks to bring the foot into a walking position. A total of 274 patients had a functional brace that facilitated immediate weight-bearing. The foot position was adjusted within the brace over the same 8-week period.

MAIN OUTCOME MEASURES

Achilles Tendon Rupture Score is patient reported and assesses symptoms and physical activity related to the Achilles tendon (score 0-100, with 100 being the best possible outcome). The secondary outcomes were quality of life, complications and resource use at 8 weeks and at 3, 6 and 9 months.

RESULTS

Participants had a mean age of 48.7 years, were predominantly male (79%) and had ruptured their tendon during sports (70%). Over 93% of participants completed follow-up. There was no statistically significant difference in Achilles Tendon Rupture Score at 9 months post injury (-1.38, 95% confidence interval -4.9 to 2.1). There was a statistically significant difference in Achilles Tendon Rupture Score at 8 weeks post injury in favour of the functional brace group (5.53, 95% confidence interval 2.0 to 9.1), but not at 3 or 6 months post injury. Quality of life showed the same pattern, with a statistically significant difference at 8 weeks post injury but not at later time points. Complication profiles were similar in both groups. Re-rupture of the tendon occurred 17 times in the plaster cast group and 13 times in the functional brace group. There was no difference in resource use.

CONCLUSIONS

This trial provides strong evidence that early weight-bearing in a functional brace provides similar outcomes to traditional plaster casting and is safe for patients receiving non-operative treatment of Achilles tendon rupture. The probability that functional bracing is cost-effective exceeds 95% for the base-case imputed analysis, assuming a cost-effectiveness threshold of £20,000 per quality-adjusted life-year. On average, functional brace is associated with lower costs (-£103, 95% confidence interval -£290 to £84) and more quality-adjusted life-years (0.015, 95% confidence interval -0.0013 to 0.030) than plaster cast.

LIMITATIONS

Some patients declined to participate in the trial, but only a small proportion of these declined because they had a preference for one treatment or another. Overall, 58% of eligible patients agreed to participate, so the participants are broadly representative of the population under investigation.

FUTURE WORK

Although the UK Study of Tendo Achilles Rehabilitation provides guidance with regard to early management, rehabilitation following Achilles tendon rupture is prolonged and further research is required to define the optimal mode of rehabilitation after the initial cast/brace has been removed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN62639639.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 8. See the NIHR Journals Library website for further project information.

Manipulative Therapy Plus Ankle Therapeutic Exercises for Adolescent Baseball Players with Chronic Ankle Instability: A Single-Blinded Randomized Controlled Trial

Manipulative therapies and exercises are commonly used for the management of chronic ankle instability (CAI), but there is no evidence regarding the efficacy of high-velocity low-amplitude manipulation (HVLA) in addition to ankle therapeutic exercise to improve CAI in adolescent baseball players (ABP). To compare the effects of HVLA plus ankle therapeutic exercise and ankle therapeutic exercise alone on ankle status, pain intensity, pain pressure threshold (PPT), range of motion (ROM) of the ankle joint, and balance ability in ABP with CAI, a single-blinded randomized controlled trial was conducted. A total of 31 ABP with CAI were randomly allocated to the intervention (n = 16) or control (n = 15) groups. The intervention group received HVLA plus resistance exercise twice a week for 4 weeks, while the control group received resistance exercise alone. Ankle status, pain intensity, PPT, ROM, and balance ability were assessed before and after the intervention. The American Orthopedic Foot and Ankle Society scores showed significant group and time interactions (total, p = 0.002; pain, p < 0.001; alignment, p = 0.001). There were significant group and time interactions in pain intensity (resting pain, p = 0.008; movement pain, p < 0.001). For ROM, there were significant group and time interactions on dorsiflexion (p = 0.006) and eversion (p = 0.026). The unipedal stance of the balance ability showed significant group and time interactions in path length (p = 0.006) and velocity (p = 0.006). Adding HVLA to resistance exercises may be synergistically effective in improving the ankle status, pain intensity, ROM, and balance ability in ABP with CAI.

Plaster cast versus functional brace for non-surgical treatment of Achilles tendon rupture (UKSTAR): a multicentre randomised controlled trial and economic evaluation

BACKGROUND

Patients with Achilles tendon rupture who have non-operative treatment have traditionally been treated with immobilisation of the tendon in plaster casts for several weeks. Functional bracing is an alternative non-operative treatment that allows earlier mobilisation, but evidence on its effectiveness and safety is scarce. The aim of the UKSTAR trial was to compare functional and quality-of-life outcomes and resource use in patients treated non-operatively with plaster cast versus functional brace.

METHODS

UKSTAR was a pragmatic, superiority, multicentre, randomised controlled trial done at 39 hospitals in the UK. Patients (aged ≥16 years) who were being treated non-operatively for a primary Achilles tendon rupture at the participating centres were potentially eligible. The exclusion criteria were presenting more than 14 days after injury, previous rupture of the same Achilles tendon, or being unable to complete the questionnaires. Eligible participants were randomly assigned (1:1) to receive a plaster cast or functional brace using a centralised web-based system. Because the interventions were clearly visible, neither patients nor clinicians could be masked. Participants wore the intervention for 8 weeks. The primary outcome was patient-reported Achilles tendon rupture score (ATRS) at 9 months, analysed in the modified intention-to-treat population (all patients in the groups to which they were allocated, excluding participants who withdrew or died before providing any outcome data). The main safety outcome was the incidence of tendon re-rupture. Resource use was recorded from a health and personal social care perspective. The trial is registered with ISRCTN, ISRCTN62639639.

FINDINGS

Between Aug 15, 2016, and May 31, 2018, 1451 patients were screened, of whom 540 participants (mean age 48·7 years, 79% male) were randomly allocated to receive plaster cast (n=266) or functional brace (n=274). 527 (98%) of 540 were included in the modified intention-to-treat population, and 13 (2%) were excluded because they withdrew or died before providing any outcome data. There was no difference in ATRS at 9 months post injury (cast group n=244, mean ATRS 74∙4 [SD 19∙8]; functional brace group n=259, ATRS 72∙8 [20∙4]; adjusted mean difference -1∙38 [95% CI -4∙9 to 2∙1], p=0·44). There was no difference in the rate of re-rupture of the tendon (17 [6%] of 266 in the plaster cast group vs 13 [5%] of 274 in the functional brace group, p=0·40). The mean total health and personal social care cost was £1181 for the plaster cast group and £1078 for the functional bract group (mean between-group difference -£103 [95% CI -289 to 84]).

INTERPRETATION

Traditional plaster casting was not found to be superior to early weight-bearing in a functional brace, as measured by ATRS, in the management of patients treated non-surgically for Achilles tendon rupture. Clinicians may consider the use of early weight-bearing in a functional brace as a safe and cost-effective alternative to plaster casting.

FUNDING

UK National Institute for Health Research Health Technology Assessment Programme.

Post-operative rehabilitation in ankle and hindfoot/midfoot fusion and reconstruction surgery - A scoping survey of UK foot and ankle surgeons and allied health professionals

OBJECTIVE

There has recently been a paradigm shift in the management of Achilles tendon rupture and ankle fracture rehabilitation with emphasis on early mobilisation. There is, however, no consensus on post-operative rehabilitation for hind/mid-foot fusion and reconstructive surgery.The aim was to scope the post-operative rehabilitation practices of UK foot and ankle surgeons and allied health professionals (AHPs).

METHODS

A 10 question online survey was sent to UK surgeons and AHPs via specialist interest groups in February 2019. Quantitative and qualitative data were analysed.

RESULTS

117 surgeons and 55 AHPs responded. There was good agreement between survey responses in the 2 groups. Fifty percent reported that they followed a local post-operative rehabilitation protocol. More than half of respondents (57%) reported that not all patients were referred for post-operative rehabilitation. There was a wide variation in the time point at which patients were instructed to weight bear (2 weeks to >12-weeks). Non-union was a concern of early mobilisation as highlighted by 62% of respondents. Qualitative themes identified were: treatment tailored to individual patients, lack of knowledge about the patient journey, treatment tailored to surgeon preferences, lack of a pathway, variation in practice.

CONCLUSIONS

There is a wide variation in the post-op rehabilitation of patients undergoing this surgery in the UK, with a lack of published research in this area. Early rehabilitation could improve patient outcomes, yet the risk of non-union is a major concern. Further research in the form of a multicentre trial is warranted to answer this research question.

The need for a paradigm shift in the rehabilitation of elective foot and ankle reconstructive surgery patients? An annotation

Current surgeon established protocols encourage late weight bearing and prolonged immobilisation after ankle, hind- and mid-foot fusion surgery. There is no universal guidance regarding early mobilisation and rehabilitation after this type of surgery. There is a paucity of research in this area but early mobilisation may be beneficial in terms of improved clinical and patient reported outcome measures, whilst still offering good union and very few complications. Feasibility work prior to a full-scale trial is now needed to explore the efficacy of early functional mobilisation, prior to any adoption within clinical practice. A paradigm shift in the early post-operative management of this patient group has the potential to improve outcomes for patients and decrease the socioeconomic burden on the health service.

Efficacy of early controlled motion of the ankle compared with immobilisation in non-operative treatment of patients with an acute Achilles tendon rupture: an assessor-blinded, randomised controlled trial

Background

Early controlled motion (ECM) of the ankle is widely used in the non-operative treatment of acute Achilles tendon rupture, although its safety and efficacy have not been investigated properly in a randomised set-up.

Purpose/Aim of the study

To investigate if ECM of the ankle was superior to immobilisation in the treatment of acute Achilles tendon rupture.

Materials and methods

This was an assessor-blinded, randomised controlled trial with patients allocated in a 1:1 ratio to one of two parallel groups. Patients aged 18–70 years were eligible for inclusion. The ECM group performed movements of the ankle five times a day from week 3 to week 8 after rupture. The control group was immobilised for 8 weeks. The primary outcome was the Achilles tendon Total Rupture Score (ATRS) evaluated at 1-year postinjury. The secondary outcomes were heel-rise work test (HRW), Achilles tendon elongation and rate of rerupture. Analysis was conducted as intention-to-treat using inverse probability weighting.

Findings/Results

189 patients were assessed for eligibility and 130 were included from February 2014 to December 2016. There were 64 patients in the ECM group and 58 in the immobilisation group. There were no statistically significant differences (p>0.3) between the ECM and the immobilisation groups at 1 year: mean (SD) ATRS was 74 (18) and 75 (18), respectively. HRW was 60% (21) and 60% (21) of the uninjured limb, and elongation was 18 mm (13) and 16 mm (11), respectively. Correspondingly, there were six and seven reruptures.

Conclusions

ECM revealed no benefit compared with immobilisation in any of the investigated outcomes.

Trial registration number

NCT02015364

Biomechanical properties of different techniques used in vitro for suturing mid-substance Achilles tendon ruptures

BACKGROUND

The Dresden technique preserves the paratenon during Achilles tendon repair and may improve the plantarflexor mechanism when combined with mobilization during early rehabilitation. However, the surgical repair design for Achilles tendon ruptures can affect rates of re-rupture or lengthening. Therefore, the aim of this study was to determine the biomechanical properties of the Krackow, Double-Kessler, Double-Dresden, and Triple-Dresden techniques used for repairing mid-substance Achilles tendon ruptures during cyclical and maximum traction.

METHODS

Sixty mid-substance bovine tendons repaired after transverse rupturing were divided randomly into four groups by repair technique: Krackow, Double-Kessler, Double-Dresden, and Triple-Dresden. Cyclical tractions of 4.7, 5.8, 7.9, and 11.7mm (equivalent to 5°, 8°, 10°, and 15° of dorsal flexion, respectively) were applied to determine gapping, tensile strength, nominal suture stress, repair deformation, and specimens with clinical failure (gap>5mm). Maximal traction was applied to measure maximum strength and failure type (i.e. suture, knot, or tendon).

FINDINGS

The Triple-Dresden technique resulted in decreased gapping, nominal suture stress, repair deformation, and quantity of specimens with clinical failure as compared to the other techniques. Furthermore, Triple-Dresden tendons showed greater comparative tensile and maximum strength. During maximal traction testing, this technique presented tendon failure, whereas the Krackow, Double-Kessler, and Double-Dresden techniques had suture failures.

INTERPRETATION

Triple-Dresden repair results in better cyclical and maximum traction strengths, suggesting that this technique might be more appropriate when performing early mobilization after mid-substance Achilles tendon rupture repair.

Cast versus functional brace in the rehabilitation of patients treated non-operatively for a rupture of the Achilles tendon: protocol for the UK study of tendo achilles rehabilitation (UK STAR) multi-centre randomised trial

INTRODUCTION

Achilles tendon rupture affects over 11 000 people yearly in the UK, and the incidence is increasing. Controversy remains with regard to the best rehabilitation strategy for these patients. In operatively treated patients, functional bracing provides better outcomes compared with plaster casts. However, the role of functional bracing in non-operatively managed patients is unclear. This is the protocol for a multicentre randomised trial of plaster cast immobilisation versus functional bracing for patients with a non-operatively managed Achilles tendon rupture.

METHODS AND ANALYSIS

All adults presenting with a primary rupture of the Achilles tendon will be screened. Non-operatively treated patients will be eligible to take part in the trial. Broad eligibility criteria will ensure that the results of the study can be generalised to the wider patient population. Randomisation will be on a 1:1 basis. Both rehabilitation strategies are widely used within the National Health Service. Standardised protocols will be followed, and details of plaster material and brace will be as per the site's usual practice.A minimum of 330 patients will be randomised to obtain 90% power to detect a difference of 8 points in Achilles Tendon Total Rupture Score at 9 months. Quality of life and resource use will be collected at 3, 6 and 9 months. The differences between treatment groups will be assessed on an intention-to-treat basis. The results of the trial-based economic evaluation will be expressed in terms of incremental cost per quality-adjusted life-year gained.

ETHICS AND DISSEMINATION

The National Research Ethic Committee approved this study on 18 March 2016 (16/SC/0109).The National Institute for Health Research Health Technology Assessment monograph and a manuscript to a peer-reviewed journal will be submitted on completion of the trial (summer 2019). The results of this trial will substantially inform clinical practice on the clinical and cost-effectiveness of the treatment of this injury. This study has been registered on the International Standard Randomised Controlled Trial Number registry with reference no ISRCTN62639639.

Temporal Healing of Achilles Tendons After Injury in Rodents Depends on Surgical Treatment and Activity

INTRODUCTION

Achilles tendon ruptures affect 15 of 100,000 women and 55 of 100,000 men each year. Controversy continues to exist regarding optimal treatment and rehabilitation protocols. The objective of this study was to investigate the temporal effects of surgical repair and immobilization or activity on Achilles tendon healing and limb function after complete transection in rodents.

METHODS

Injured tendons were repaired (n = 64) or left nonrepaired (n = 64). The animals in both cohorts were further randomized into groups immobilized in plantar flexion for 1, 3, or 6 weeks that later resumed cage and treadmill activity for 5, 3, or 0 weeks, respectively (n = 36 for each regimen), which were euthanized at 6 weeks after injury, or into groups immobilized for 1 week and then euthanized (n = 20).

RESULTS

At 6 weeks after injury, the groups that had 1 week of immobilization and 5 weeks of activity had increased range of motion and decreased ankle joint toe stiffness compared with the groups that had 3 weeks of immobilization and 3 weeks of activity. The groups with 6 weeks of immobilization and no activity period had decreased tendon cross-sectional area but increased tendon echogenicity and collagen alignment. Surgical treatment dramatically decreased fatigue cycles to failure in repaired tendons from groups with 1 week of immobilization and 5 weeks of activity. Normalized comparisons between 1-week and 6-week postinjury data demonstrated that changes in tendon healing properties (area, alignment, and echogenicity) were maximized by 1 week of immobilization and 5 weeks of activity, compared with 6 weeks of immobilization and no activity period.

DISCUSSION

This study builds on an earlier study of Achilles tendon fatigue mechanics and functional outcomes during early healing by examining the temporal effects of different immobilization and/or activity regimens after initial postinjury immobilization.

CONCLUSION

This study demonstrates how the temporal postinjury healing response of rodent Achilles tendons depends on both surgical treatment and the timing of immobilization/activity timing. The different pattern of healing and qualities of repaired and nonrepaired tendons suggest that two very different healing processes may occur, depending on the chosen immobilization/activity regimen.

Clinical failure after Dresden repair of mid-substance Achilles tendon rupture: human cadaveric testing

PURPOSE

The purpose of this study was to describe the angle of clinical failure during cyclical mobilization exercises in the Achilles tendon of human cadaveric specimens that were repaired using the Dresden technique and FiberWire^® No. 2. The secondary aim was to identify the secure limit of mobilization, the type of failure, and the type of apposition.

METHODS

The lower limbs of eight males (mean age: 60.3 ± 6.3 years) were repaired with the Dresden technique following complete, percutaneous mid-substance Achilles tendon rupture. A basal tension of 10 N at 30° of plantarflexion was placed on each specimen. The angle of the ankle during clinical failure (tendon ends separation >5 mm) was then tested via cyclical exercises (i.e. 100 cycles between 30° and 15° of plantarflexion; 100 cycles between 15° of plantarflexion and 0°; 100 cycles between 0° and 15° of dorsiflexion; and 100 cycles between 15° of dorsiflexion and full dorsiflexion). Clinical failure was determined using the Laplacian edge detection filter, and the angle of clinical failure was obtained using a rotatory potentiometer aligned in relation to the intermalleolar axis of each foot specimen. The type of failure (knot, tendon, or suture) and apposition (termino-terminal or non-termino-terminal) were determined. Descriptive statistics were used to obtain the mean; standard deviation; 95 % confidence interval; 1st, 25th, 50th, 75th, and 100th percentiles; and the standard error of the mean for angle data. Proportions were used to describe the type of failure and apposition.

RESULTS

The main results were a mean angle of clinical failure equal to 12.5° of plantarflexion, a limit of mobilization equal to 14.0° of plantarflexion, tendon failure type, and non-termino-terminal apposition in all specimens.

CONCLUSIONS

While the mean angle of clinical failure in human cadaveric models was 12.5° of plantarflexion, after 14.0° of plantarflexion, the percutaneous Dresden technique was found insecure for cyclical mobilization exercises, with a 5 % range of error. These findings are clinically relevant as they provide mechanical limits for diminishing the risk of Achilles lengthening during immediate rehabilitation.

Rehabilitation of Achilles tendon ruptures: is early functional rehabilitation daily routine?

INTRODUCTION

Ruptures of the Achilles tendon are the most common tendon injuries of the lower extremities. Besides the initial operative or non-operative treatment, rehabilitation of patients plays a crucial role for tendon healing and long-term outcome. As only limited evidence is available for optimized rehabilitation regimen and guidelines for the initial (e.g., first 6 weeks) rehabilitation are limited, this study investigated the current rehabilitation concepts after Achilles tendon rupture.

MATERIALS AND METHODS

We analyzed 213 written rehabilitation protocols that are provided by orthopedic and trauma surgery institutions throughout Germany in terms of recommendations for weight-bearing, range of motion (ROM), physiotherapy, and choice of orthosis. All protocols for operatively and non-operatively treated Achilles tendon ruptures were included. Descriptive analysis was carried out and statistical analysis applied where appropriate.

RESULTS

Of 213 institutions, 204 offered rehabilitation protocols for Achilles tendon rupture and, therefore, 243 protocols for operative and non-operative treatment could be analyzed. While the majority of protocols allowed increased weight-bearing over time, significant differences were found for durations of fixed plantar flexion between operative (o) and non-operative (n) treatments [fixed 30° (or 20)° to 15° (or 10)°: 3.6 weeks (±0.1; o) vs 4.7 weeks (±0.3; n) (p ≤ 0.0001) and fixed 15° (or 10)° to 0°: 5.8 weeks (±0.1; o) vs 6.6 weeks (±0.2; n) (p ≤ 0.001)]. The mean time of the recommended start of physiotherapy is at 2.9 weeks (±0.2; o) vs 3.3 weeks (±0.4; n), respectively.

CONCLUSION

Our study shows that a huge variability in rehabilitation after Achilles tendon rupture exists. This study shows different strategies in rehabilitation of Achilles tendon ruptures using a convertible vacuum brace system. To improve patient care, further clinical as well as biomechanical studies need to be conducted. This study might serve as basis for prospective randomized controlled trials to optimize rehabilitation for Achilles tendon ruptures.

Medial Gastrocnemius Myotendinous Junction Displacement and Plantar-Flexion Strength in Patients Treated With Immediate Rehabilitation After Achilles Tendon Repair

CONTEXT

Pathologic plantar flexion frequently occurs after operative repair of the Achilles tendon (AT) because of immobilization and non-weight bearing in the first weeks of traditional rehabilitation. Novel rehabilitation strategies that apply mobilization and weight bearing have been proposed, but their effects on medial gastrocnemius myotendinous junction displacement (MJD) and isometric plantar-flexion strength (PFS) are unknown.

OBJECTIVE

To compare the effects of 12 weeks of immediate versus traditional rehabilitation on MJD and PFS in patients with percutaneous AT repair and to compare AT rupture scores (ATRSs) during follow-up.

DESIGN

Controlled laboratory study.

SETTING

Human performance laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 26 amateur soccer players (age = 42.3 ± 9.7 years, body mass index = 29.5 ± 3.9 kg/m²) with percutaneous AT repair.

INTERVENTION(S)

Athletes were randomly divided into 2 groups: an immediate group, given physical therapy from day 1 to day 84, and a traditional group, given physical therapy from day 29 to day 84. We used repeated-measures analysis of variance to compare the data.

MAIN OUTCOME MEASURE(S)

We measured MJD and PFS at days 28 (fourth week), 56 (eighth week), and 84 (12th week) after AT repair.

RESULTS

After 12 weeks of rehabilitation, we observed a large clinically meaningful effect and statistical difference between groups. At day 28, the immediate group showed higher values for PFS (P = .002), MJD (P = .02), and ATRS (P = .002) than the traditional group. At day 56, the immediate group presented higher values for MJD (P = .02) and ATRS (P = .009). At day 84, the immediate group registered more MJD (P = .001).

CONCLUSIONS

Compared with traditional rehabilitation, 12 weeks of immediate rehabilitation after percutaneous AT repair resulted in better MJD, PFS, and ATRS after 4 weeks; better MJD and ATRS after 8 weeks; and better MJD after 12 weeks.

Nonsurgical treatment and early return to activity leads to improved Achilles tendon fatigue mechanics and functional outcomes during early healing in an animal model

Achilles tendon ruptures are common and devastating injuries; however, an optimized treatment and rehabilitation protocol has yet to be defined. Therefore, the objective of this study was to investigate the effects of surgical repair and return to activity on joint function and Achilles tendon properties after 3 weeks of healing. Sprague-Dawley rats (N = 100) received unilateral blunt transection of their Achilles tendon. Animals were then randomized into repaired or non-repaired treatments, and further randomized into groups that returned to activity after 1 week (RTA1) or after 3 weeks (RTA3) of limb casting in plantarflexion. Limb function, passive joint mechanics, and tendon properties (mechanical, organizational using high frequency ultrasound, histological, and compositional) were evaluated. Results showed that both treatment and return to activity collectively affected limb function, passive joint mechanics, and tendon properties. Functionally, RTA1 animals had increased dorsiflexion ROM and weight bearing of the injured limb compared to RTA3 animals 3-weeks post-injury. Such functional improvements in RTA1 tendons were evidenced in their mechanical fatigue properties and increased cross sectional area compared to RTA3 tendons. When RTA1 was coupled with nonsurgical treatment, superior fatigue properties were achieved compared to repaired tendons. No differences in cell shape, cellularity, GAG, collagen type I, or TGF-β staining were identified between groups, but collagen type III was elevated in RTA3 repaired tendons. The larger tissue area and increased fatigue resistance created in RTA1 tendons may prove critical for optimized outcomes in early Achilles tendon healing following complete rupture. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2172-2180, 2016.

Efficacy of early controlled motion of the ankle compared with no motion after non-operative treatment of an acute Achilles tendon rupture: study protocol for a randomized controlled trial

BACKGROUND

Early controlled ankle motion is widely used in the non-operative treatment of acute Achilles tendon rupture, though its safety and efficacy have never been investigated in a randomized setup. The objectives of this study are to investigate if early controlled motion of the ankle affects functional and patient-reported outcomes.

METHODS/DESIGN

The study is performed as a blinded, randomized, controlled trial with patients allocated in a 1:1 ratio to one of two parallel groups. Patients aged from 18 to 70 years are eligible for inclusion. The intervention group performs early controlled motion of the ankle in weeks 3-8 after rupture. The control group is immobilized. In total, 130 patients will be included from one big orthopedic center over a period of 2½ years. The primary outcome is the patient-reported Achilles tendon Total Rupture Score evaluated at 12 months post-injury. Secondary outcome measures are the heel-rise work test, Achilles tendon elongation, and the rate of re-rupture. The primary analysis will be conducted as intention-to-treat analyses.

DISCUSSION

This trial is the first to investigate the safety and efficacy of early controlled motion in the treatment of acute Achilles tendon rupture in a randomized setup. The study uses the patient-reported outcome measure, the Achilles tendon Total Rupture Score, as the primary endpoint, as it is believed to be the best surrogate measure for the tendon's actual capability to function in everyday life.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02015364 . Registered on 13 December 2013.

Is the Dresden technique a mechanical design of choice suitable for the repair of middle third Achilles tendon ruptures? A biomechanical study

OBJECTIVE

To compare the mechanical failure of the Dresden technique for Achilles tendon repair with the double modified Kessler technique controlled repair technique. The maximum resistance of the two repair techniques are also compared.

MATERIAL AND METHODS

A total of 30 Achilles tendon ruptures in bovine specimens were repaired with an Ethibond(®) suture to 4.5cm from the calcaneal insertion. Each rupture was randomly distributed into one of two surgical groups. After repair, each specimen was subjected to a maximum traction test. The mechanical failure (tendon, suture, or knot) rates (proportions) were compared using the exact Fisher test (α=.05), and the maximum resistances using the Student t test (α=.05).

RESULTS

There was a difference in the proportions of mechanical failures, with the most frequent being a tendon tear in the Dresden technique, and a rupture of the suture in the Kessler technique.

DISCUSSION

The repair using the Dresden technique performed in the open mode, compared to the Kessler technique, has a more suitable mechanical design for the repair of middle third Achilles tendon ruptures on developing a higher tensile resistance in 58.7%. However, its most common mechanical failure was a tendon tear, which due to inappropriate loads could lead to lengthening of the Achilles tendon.

Prospective randomized clinical trial of aggressive rehabilitation after acute Achilles tendon ruptures repaired with Dresden technique

BACKGROUND

Rupture of the Achilles tendon is a common injury during working years. Aggressive rehabilitation may provide better outcomes, but also a greater chance of re-rupture.

OBJECTIVE

To determine if aggressive rehabilitation has better clinical outcomes for Achilles tendon function, Triceps surae function, one-leg heel rise capacity and lower complication rate during twelve weeks after percutaneous Achilles tendon repair compared to conventional rehabilitation.

DESIGN

Randomized controlled trial.

METHOD

Thirty-nine patients were prospectively randomized. The aggressive group (n=20, 41.4 ± 8.3 years) received rehabilitation from the first day after surgery. The conventional group (n=19, 41.7 ± 10.7 years) rested for 28 days, before rehabilitation started. The statistical parameters were the Achilles tendon rupture score (ATRS), verbal pain scale, time to return to work, pain medication consumption, Achilles tendon strength, dorsiflexion range of motion (RoM), injured-leg calf circumference, calf circumference difference, one-leg heel rise repetition and difference, re-rupture rate, strength deficit rate, and other complication rates. Mixed-ANOVA and Bonferroni's post hoc test were performed for multiple comparisons. Student's t-test was performed for parameters measured on the 12th week.

RESULTS

The aggressive group with respect to the conventional group had a higher ATRS; lower verbal pain score; lower pain medication consumption; early return to work; higher Achilles tendon strength; higher one-leg heel rise repetitions; and lower one-leg heel rise difference. The re-rupture rate was 5% and 5%, the strength deficit rate was 42% and 5%, and other complications rate was 11% and 15% in the conventional and aggressive group, respectively.

CONCLUSION

Patients with Dresden repair and aggressive rehabilitation have better clinical outcomes, Achilles tendon function and one-leg heel rise capacity without increasing the postoperative complications rate after 12 weeks compared to rehabilitation with immobilization and non-weight-bearing during the first 28 days after surgery.

Percutaneous, Minimally Invasive Repair of Traumatic and Simultaneous Rupture of Both Achilles Tendons: A Case Report

Achilles injury is a common musculoskeletal disorder. Bilateral rupture of the Achilles tendon, however, is much less common and usually occurs spontaneously. Complete, traumatic, and bilateral ruptures are rare and typically require long periods of immobilization before the patient can return to full weightbearing. A 52-year-old male was hospitalized for bilateral traumatic rupture to both Achilles tendons. No risk factors for tendon rupture were found. Blood samples revealed no peripheral blood pathologic features. Both tendons were repaired with percutaneous, minimally invasive surgery using the Achillon(®) tendon suture system. Rehabilitation was begun 4 weeks later. An ankle-foot orthosis was prescribed to provide ankle support with an adjustable range of movement, and active plantar flexion was set at 0° to 30°. The patient remained non-weightbearing with the ankle-foot orthosis device and performed active range-of-motion exercises. At 8 weeks after surgery, we recommended that he begin walking with partial weightbearing using a foot-tibial orthosis with the range of motion set to 45° plantar flexion and 15° dorsiflexion. At 10 weeks postoperatively, he was encouraged to return to full weightbearing on both feet. Beginning rehabilitation as soon as possible after minimally invasive surgery, compared with 6 weeks of immobilization after surgery, provided a rapid resumption to full weightbearing. We emphasize the clinical importance of a safe, simple treatment program that can be followed for a patient with damage to the Achilles tendons. To our knowledge, ours is the first report of minimally invasive repair of bilateral simultaneous traumatic rupture of the Achilles tendon.

Achilles tendon rupture rehabilitation: a mixed methods investigation of current practice among orthopaedic surgeons in the United Kingdom

OBJECTIVES

The evidence base to inform the management of Achilles tendon rupture is sparse. The objectives of this research were to establish what current practice is in the United Kingdom and explore clinicians' views on proposed further research in this area. This study was registered with the ISRCTN (ISRCTN68273773) as part of a larger programme of research.

METHODS

We report an online survey of current practice in the United Kingdom, approved by the British Orthopaedic Foot and Ankle Society and completed by 181 of its members. A total of ten of these respondents were invited for a subsequent one-to-one interview to explore clinician views on proposed further research in this area.

RESULTS

The survey showed wide variations in practice, with patients being managed in plaster cast alone (13%), plaster cast followed by orthoses management (68%), and orthoses alone (19%). Within these categories, further variation existed regarding the individual rehabilitation facets, such as the length of time worn, the foot position within them and weight-bearing status. The subsequent interviews reflected this clinical uncertainty and the pressing need for definitive research.

CONCLUSIONS

The gap in evidence in this area has resulted in practice in the United Kingdom becoming varied and based on individual opinion. Future high-quality randomised trials on this subject are supported by the clinical community. Cite this article: Bone Joint Res 2015;4:65-9.

Rehabilitation regimen after surgical treatment of acute Achilles tendon ruptures: a systematic review with meta-analysis

BACKGROUND

The choice of rehabilitation management after the surgical repair of acute Achilles tendon (AT) ruptures remains controversial because of insufficient clinical evidence. The current study analyzes the postoperative rehabilitation of AT ruptures based on the current clinical evidence.

PURPOSE

To identify and analyze the high-level clinical evidence regarding postoperative rehabilitation after the surgical repair of AT ruptures. Subgroup analyses were also performed to obtain more reliable and specific results.

STUDY DESIGN

Meta-analysis.

METHODS

The studies were retrieved by searching the Medline, Embase, and Cochrane databases through the OVID retrieval engine from 1990 to August 14, 2013. Two independent reviewers critically reviewed the studies using preset inclusion and exclusion criteria. The quality of the eligible studies was assessed by the Cochrane 12-item scale. All included studies were summarized, and their data were extracted. Subgroup analyses were performed according to the different protocols of early functional rehabilitation.

RESULTS

Nine studies, consisting of 6 randomized controlled trials and 3 quasi-randomized studies, were ultimately included. A total of 402 patients were identified. Six of the included studies utilized early weightbearing combined with early ankle motion exercises, while the other 3 only employed early ankle motion exercises. The subgroup analyses demonstrated that 11 of the 15 functional outcome measurements were significantly superior for patients who underwent both early weightbearing and ankle motion exercises than for those who underwent conventional cast immobilization. Similar rates of reruptures (odds ratio [OR], 1.36; 95% CI, 0.38-4.91; P = .64) and major complications (OR, 0.67; 95% CI, 0.24-1.87; P = .44) as well as a significantly lower rate of minor complications (OR, 0.51; 95% CI, 0.27-0.95; P = .03) were also observed in this early functional rehabilitation group. For the patients who solely performed early ankle motion exercises, only 2 of the 14 functional measurements were observed to be significantly superior to immobilization. There were also no significant differences in the rates of reruptures (OR, 0.47; 95% CI, 0.08-2.70; P = .40) and other complications (OR, 1.09; 95% CI, 0.41-2.92; P = .86) between the 2 groups.

CONCLUSION

Postoperative early weightbearing combined with early ankle motion exercises is associated with a lower minor complication rate and achieves superior and more rapid functional recovery than conventional immobilization after surgical AT repair. In contrast, few advantages were identified when only early ankle motion exercises were applied.

Progress in cell-based therapies for tendon repair

The last decade has seen significant developments in cell therapies, based on permanently differentiated, reprogrammed or engineered stem cells, for tendon injuries and degenerative conditions. In vitro studies assess the influence of biophysical, biochemical and biological signals on tenogenic phenotype maintenance and/or differentiation towards tenogenic lineage. However, the ideal culture environment has yet to be identified due to the lack of standardised experimental setup and readout system. Bone marrow mesenchymal stem cells and tenocytes/dermal fibroblasts appear to be the cell populations of choice for clinical translation in equine and human patients respectively based on circumstantial, rather than on hard evidence. Collaborative, inter- and multi-disciplinary efforts are expected to provide clinically relevant and commercially viable cell-based therapies for tendon repair and regeneration in the years to come.

Accelerated rehabilitation following Achilles tendon repair after acute rupture - Development of an evidence-based treatment protocol

The acute rupture of the Achilles tendon is a protracted injury. Surgery is only the beginning of a long rehabilitation period. Therefore, the rehabilitation protocol is an integral aspect to restore the pre-injury activity level. Despite several trials available comparing different treatment regimes, there is still no consensus regarding the optimal protocol. Consequently, the aim of our study was to systematically search the evidence available and define a precise rehabilitation programme after operative repair of acute Achilles tendon rupture based on the trials with the highest level of evidence. We performed a systematic literature search in Medline, Embase and Cochrane library. We identified twelve randomized controlled trials comparing different treatment regimes after operative repair of the Achilles tendon. Five trials compared full to non weight bearing, all applying immobilization in equinus. Immediate full weight bearing led to significant higher patient satisfaction, earlier ambulation and return to pre-injury activity. Four trials compared early ankle mobilization to immobilization. All trials found mobilization to be superior as it shortens time to return to work and sports significantly. Three trials compared the combination of full weight bearing and early ankle mobilization to immobilization. This combination was most beneficial. Patients showed significantly higher satisfaction, less use of rehabilitation resources, earlier return to pre-injury activities and further demonstrated significantly increased calf muscle strength, reduced atrophy and tendon elongation. No study found an increased rerupture rate for the more progressive treatment. In conclusion, the rehabilitation protocol after Achilles tendon repair should allow immediate full weight bearing. After the second postoperative week controlled ankle mobilization by free plantar flexion and limited dorsiflexion at 0° should be applied.

Microtrauma stimulates rat Achilles tendon healing via an early gene expression pattern similar to mechanical loading

Mechanical loading increases the strength of healing tendons, but also induces small localized bleedings. Therefore, it is unclear if increased strength after loading is a response to mechanotransduction or microtrauma. We have previously found only five genes to be up-regulated 15 min after a single loading episode, of them four were transcription factors. These genes are followed by hundreds of genes after 3 h, many of them involved in inflammation. We now compared healing in mechanically unloaded tendons with or without added microtrauma induced by needling of the healing tissue. Nineteen rats received Botox into the calf muscle to reduce loading, and the Achilles tendon was transected. Ten rats were randomized to needling days 2–5. Mechanical testing on day 8 showed increased strength by 45% in the needling group. Next, another 24 rats were similarly unloaded, and 16 randomized to needling on day 5 after transection. Nineteen characteristic genes, known to be regulated by loading in this model, were analyzed by qRT-PCR. Four of these genes were regulated 15 min after needling. Three of them (Egr1, c-Fos, Rgs1) were among the five regulated genes after loading in a previous study. Sixteen of the 19 genes were regulated after 3 h, in the same way as after loading. In conclusion, needling increased strength, and there was a striking similarity between the gene expression response to needling and mechanical loading. This suggests that the response to loading in early tendon healing can, at least in part, be a response to microtrauma.

Achilles tendon ruptures

The incidence of acute Achilles tendon ruptures is on the rise. This is thought to be due to the increasing number of middle-aged persons participating in athletic and/or strenuous activity. Ruptures of the Achilles tendon can be severely debilitating, with deficits seen years after the initial incident. Also, these injuries can have substantial socioeconomic impacts regardless of the treatment selected. Debate continues over the optimal treatment of Achilles tendon ruptures, especially the argument whether to treat patients nonoperatively or surgically. Newer evidence shows that functional rehabilitation, including early weight-bearing, should be an integral part of successful treatment of acute Achilles ruptures. Further research is needed to further investigate the ideal treatment and rehabilitation protocols.

Early controlled tension improves the material properties of healing human achilles tendons after ruptures: a randomized trial

BACKGROUND

Weightbearing in a fixed brace after acute Achilles tendon ruptures does not necessarily lead to mechanical tension in the tendon. Early motion has a positive effect on the clinical outcome, but it is not clear if this is because of effects on tendon strength or unspecific effects. The aim of this study was to examine if tensional loading leads to an improvement in the mechanical properties of the healing Achilles tendon.

HYPOTHESIS

The elastic modulus of the tendon callus is increased by early tensional loading.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Thirty-five patients with an acute Achilles tendon rupture were recruited consecutively. They underwent surgery with a single suture and received metal markers in the distal and proximal parts of the tendon. After surgery, the patients were randomized to either cast immobilization for 7 weeks or tensional loading. The latter group wore a cast for 2 weeks and then a removable foam walker boot for 5 weeks. They were instructed to remove the boot twice daily and push a special training pedal to produce a predetermined, gradually increasing tensional load on the healing tendon. At 7, 19, and 52 weeks postoperatively, the patients were investigated with roentgen stereophotogrammetric analysis under different loading conditions and computed tomography. The collected data allowed calculation of the modulus of elasticity. At 52 weeks, the clinical outcome was also examined using the Achilles tendon Total Rupture Score (ATRS) and the heel-raise index.

RESULTS

The elastic modulus at 19 and 52 weeks was higher in the tensional loading group. There was no significant difference in the ATRS or heel-raise index at 52 weeks. As in previous studies, there was a significant correlation between the modulus at 7 weeks and the heel-raise index at 52 weeks. There were no signs of tendon elongation.

CONCLUSION

Early tensional loading improves the mechanical properties of the healing Achilles tendon.

Augmentation of tendon healing with butyric acid-impregnated sutures: biomechanical evaluation in a rabbit model

BACKGROUND

Butyric acid (BA) has been shown to be angiogenic and to enhance transcriptional activity in tissue. These properties of BA have the potential to augment biological healing of a repaired tendon.

PURPOSE

To evaluate this possibility both biomechanically and histologically in an animal tendon repair model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A rabbit Achilles tendon healing model was used to evaluate the biomechanical strength and histological properties at 6 and 12 weeks after repair. Unilateral tendon defects were created in the middle bundle of the Achilles tendon of each rabbit, which were repaired equivalently with either Ultrabraid BA-impregnated sutures or control Ultrabraid sutures.

RESULTS

After 6 weeks, BA-impregnated suture repairs had a significantly increased (P < .0001) Young's modulus and ultimate tensile strength relative to the control suture repairs. At 12 weeks, no statistical difference was observed between these measures. The histological data at 6 weeks demonstrated significantly increased (P < .005) vessel density within 0.25 mm of the repair suture in the BA-impregnated group. There was also an associated 42% increase in the local number of myofibroblasts in the BA samples relative to the controls at this time. By 12 weeks, these differences were not observed.

CONCLUSION

Tendons repaired with BA-impregnated sutures demonstrated improved biomechanical properties at 6 weeks relative to control sutures, suggesting a neoangiogenic mechanism of enhanced healing through an increased myofibroblast presence.

CLINICAL RELEVANCE

These findings demonstrate that a relatively simple alteration of suture material may augment early tendon healing to create a stronger repair construct during this time.