Relative motion orthoses for early active motion after finger extensor and flexor tendon repairs: A systematic review

BackgroundThe relative motion (RM) orthosis was introduced over 40 years ago for extensor tendon rehabilitation and more recently applied to flexor tendon repairs.PurposeWe systematically reviewed the evidence for RM orthoses following surgical repair of finger extensor and flexor tendon injuries including indications for use, configuration and schedule of orthosis wear, and clinical outcomes.Study DesignSystematic review.MethodsA PRISMA-compliant systematic review searched eight databases and five trial registries, from database inception to January 7, 2022. The protocol was registered prospectively (CRD42020211579). We identified studies describing patients undergoing rehabilitation using RM orthoses after surgical repair of acute tendon injuries of the finger and hand.ResultsFor extensor tendon repairs, ten studies, one trial registry and five conference abstracts met inclusion criteria, reporting outcomes of 521 patients with injuries in zones IV-VII. Miller's criteria were predominantly used to report range of motion; with 89.6% and 86.9% reporting good or excellent outcomes for extension lag and flexion deficit, respectively. For flexor tendon repairs, one retrospective case series was included reporting outcomes in eight patients following zones I-II repairs. Mean total active motion was 86%. No tendon ruptures were reported due to the orthosis not protecting the repair for either the RME or RMF approaches.DiscussionVariation was seen in use of RME plus or only, use of night orthoses and orthotic wear schedules, which may be the result of evolution of the RM approach. Since Hirth et al's 2016 scoping review, there are five additional studies, including two RCTs reporting the use of the RM orthosis in extensor tendon rehabilitation.ConclusionsThere is now good evidence that the RM approach is safe in zones V-VI extensor tendon repairs. Limited evidence currently exists for zones IV and VII extensor and for flexor tendon repairs. Further high-quality clinical studies are needed to demonstrate its safety and efficacy.     

Tendon injuries across the world: treatment

This article outlines current status of primary and secondary surgical treatment of flexor and extensor tendon injuries in the hand and rehabilitation regimens worldwide. Unsolved problems associated with tendon repairs in the hand are tendon adhesions, rupture of the repairs, finger stiffness, power of hand motion, and surgical skills. Future development may include improvement of tendon healing through biological approaches, repair techniques, and, in particular, establishment of adequate rehabilitation systems and training of surgeons in some regions of the world.     

Long-term results after primary repairs of zone 2 flexor tendon lacerations in children younger than age 6 years

In young children, methods of primary flexor tendon repair in the digital canal are controversial. The authors reviewed 12 children younger than age 6 years with zone 2 flexor tendon repairs. The mean follow-up period was 8 years. In all cases, the flexor digitorum profundus tendons were repaired according to the Kessler modified technique and the hands were immobilized by an above-elbow cast. As for postoperative complications, there were no fingers with tendon rupture and two fingers with tendon adhesion. One finger needed tenolysis. The total active motion (TAM) in the interphalangeal joints evaluated with the Strickland formula averaged 155 degrees, and the TAM percentage averaged 89% (range 74%-100%). Eleven patients had an excellent result and one had a good result. The percentage phalangeal length averaged 99% (range 96%-100%). Functional motion and nearly normal growth of the finger can be expected after primary zone 2 flexor tendon repairs in children younger than age 6 years.     

Relative motion flexion following zone I-III flexor tendon repair: Concepts,evidence and practice.

Study DesignNarrative review and case series.IntroductionThe relative motion approach has been applied to rehabilitation following flexor tendon repair. Positioning the affected finger(s) in relatively more metacarpophalangeal joint flexion is hypothesized to reduce the tension through the repaired flexor digitorum profundus by the quadriga effect. It is also hypothesized that altered patterns of co-contraction and co-inhibition may further reduce flexor digitorum profundus tension, and confer protection to flexor digitorum superficialis.MethodsWe reviewed the existing literature to explore the rationale for using relative motion flexion orthoses as an early active mobilization strategy for patients after zone I-III flexor tendon repairs. We used this approach within our own clinic for the rehabilitation of a series of patients presenting with zone I-II flexor tendon repair. We collected routine clinical and patient reported outcome data.ResultsWe report published outcomes of the clinical use of relative motion flexion orthoses with early active motion, implemented as the primary rehabilitation approach after zone I-III flexor digitorum repairs. We also report novel outcome data from 18 patients.DiscussionWe discuss our own experience of using relative motion flexion as a rehabilitation strategy following flexor tendon repair. We explore orthosis fabrication, rehabilitation exercises and functional hand use.ConclusionsThere is currently limited evidence informing use of relative motion flexion orthoses following flexor tendon repair. We highlight key areas for future research and describe a current pragmatic randomized controlled trial.     

The results of immediate re-repair of zone 1 and 2 primary flexor tendon repairs which rupture

This study reports the outcome of immediate re-repair of primary flexor tendon repairs in zones 1 and 2 of the fingers which had ruptured. Between June 1989 and May 2003, a total of 62 fingers in 61 patients presented with ruptured flexor tendon repairs within 48 hours from rupture. Immediate re-repair and rehabilitation was carried out in 44 fingers (71%) in 43 (70%) patients. Thirty-six patients completed the 8-week therapy programme after re-repair in 37 fingers. Nine (24%) had excellent, 10 (27%) good, 5 (14%) fair and 13 (35%) had poor results when assessed by the original Strickland method. Five fingers in five patients ruptured the re-repair. Poor results and second ruptures were particularly common after re-repair of ruptured tendon repairs in the little finger. In the light of these findings, a policy for dealing with ruptured primary flexor tendon repairs in the fingers is suggested.     

Functional outcome in patients with zone V flexor tendon injuries

Introduction Zone V flexor tendon injuries may involve major nerves and arteries as well as the wrist and finger flexors. Although these injuries are not infrequent, few studies have reported functional outcomes. The purpose of this study was to evaluate the functional outcome in patients with flexor tendon repairs in zone V.Materials and methods Eighteen patients with repaired zone V flexor tendon injuries were followed up for an average of 20 months. The postoperative rehabilitation program consisted of a combined regime of modified Kleinert and modified Duran techniques. Outcome parameters were hand function according to the Buck-Gramcko assessment system, grip and key pinch strength values, and return to work status.Results Functional results were excellent in 92.8% of the digits, good in 1.4%, and poor in 5.8%. Grip strength recovered to an average of 77% and pinch strength to 74% of the uninjured hand. Two tendon ruptures occurred in a patient, and tenolysis was required in 3 patients. Of 15 patients who were employed at the time of injury, 13 returned to their original occupations.Conclusion Satisfactory functional results can be obtained when proper surgical technique is coupled with careful postoperative management in patients with zone V flexor tendon injuries.     

The future of flexor tendon surgery

Clinical outcomes following flexor tendon repair have made significant improvements in the last 50 years. In that time standard treatment has evolved from secondary grafting to primary repair with postoperative rehabilitation protocols. Unfortunately, excellent results are not yet attained universally following treatment. Improving understanding of tendon healing at the cellular, molecular, and genetic levels will likely enable surgeons to modulate the normal repair process. We now look toward biologic augmentation of flexor tendon repairs to address the problems of increasing tensile strength while reducing adhesion formation following injury and operative repair.     

Beugesehnenverletzung der Hand

At last, flexor tendon injuries of the hand and digit are no longer nearly impossible to treat. Many recent studies have reported a more than 75% success with excellent results, in particular in zone 2, in some cases reaching 98% satisfactory outcomes. The challenge inherent in treating and rehabilitating the zone 2 flexor tendon injury remains, however, even for the skilled hand surgeon. We must remain diligent, obeying principles outlined earlier by the first surgeons willing to attempt these repairs, while carefully gleaning the helpful and critical recommendations of the now sophisticated researchers in the subject of flexor tendon repair and rehabilitation.     

Flexor tendon injuries of the hand

At last, flexor tendon injuries of the hand and digit are no longer nearly impossible to treat. Many recent studies have reported a more than 75% success with excellent results, in particular in zone 2, in some cases reaching 98% satisfactory outcomes. The challenge inherent in treating and rehabilitating the zone 2 flexor tendon injury remains, however, even for the skilled hand surgeon. We must remain diligent, obeying principles outlined earlier by the first surgeons willing to attempt these repairs, while carefully gleaning the helpful and critical recommendations of the now sophisticated researchers in the subject of flexor tendon repair and rehabilitation.     

Current practice patterns of flexor tendon rehabilitation.

The rehabilitation of persons with repaired lacerations of their finger flexor tendons requires a precise therapeutic approach. But optimal therapy is often difficult to ascertain, given the plethora of postoperative regimens published in the scientific literature. The purpose of the survey was to describe current and historical practice patterns of therapists rehabilitating intrasynovial flexor tendon repairs. Key elements were identified as surgical suture, protocol, initiation of therapy, frequency of therapy visits, initiation of active motion, discharge protective splint, initiation of resistance, proximal interphalangeal joint flexion contracture, outcomes, rupture, and general attitudes. One hundred and ninety-one therapists completed the survey. Findings suggest that Kleinert-type and Duran-type regimens are widespread. Active finger flexion is initiated at a mean of 18.6 days postoperatively. Nearly 30% of respondents utilize early active finger flexion exercise within the first postoperative week. Current practice patterns regarding the timing of the initiation of key elements vary from those reported in the literature.     

Treatment of unfavourable results of flexor tendon surgery: Ruptured repairs,tethered repairs and pulley incompetence

As primary repair of divided flexor tendons becomes more common, secondary tendon surgery becomes largely that of the complications of primary repair, namely ruptured and adherent repairs. These occur with an incidence of each in most reported series world-wide of around 5%, with these problems having changed little in the last two decades, despite strengthening our suture repairs. Where the primary referral service is less well-developed, and as a more occasional occurrence where primary treatment is the routine, the surgeon faces different problems. Patients arrive at a hand unit variable, but longer, times after the primary insult, having had no, or bad, previous treatment. Sometimes the situation is the same, viz. an extended finger with no active flexion, but now no longer amenable to primary repair. Frequently, it is much more complex as a result of injuries to the other tissues of the digit and, also, as a result of the unaided healing process within the digit in the presence of an inactive flexor system. We present our experience in dealing with ruptured repairs, tethered repairs and pulley incompetence.KEY WORDS: Flexor tendon injury, flexor tendon reconstruction, flexor tendon pulley reconstruction, secondary flexor tendon repair, tenolysis     

Implementing an internal audit to change practice: Current evidence and review of patient outcomes enabled transition to the relative motion extension approach in the postoperative management of zones IV-VI extensor tendon repairs

BackgroundEvidence supports use of the relative motion extension (RME) approach following extensor tendon repairs in zones V-VI yielding good or excellent outcomes.PurposeTo demonstrate how a 3-year internal audit and regular review of emerging evidence guided our change in practice from our longstanding use of the Norwich Regimen to the RME approach using implementation research methods. We compared the outcomes of both approaches prior to the formal adoption of the RME approach.Study DesignProspective clinical audit.MethodsA prospective audit of all consecutive adult finger extensor tendon repairs in zones IV-VII rehabilitated in our tertiary public health hand centre was undertaken between November 2014 and December 2017. Each audit year, outcomes were reviewed regarding the Norwich regimen and the RME early active motion approaches. As new evidence emerged, adjustments were made to our audit protocol for the RME approach. Discharge measurements of the range of motion of the affected and contralateral fingers and complications were recorded.ResultsDuring the 3-year audit, data was available on 79 patients (56 RME group including 59 fingers with 71 tendon repairs; 23 Norwich group including 28 fingers with 34 tendon repairs) with simple (n = 68) and complex (n = 11) finger extensor tendon zones IV-VI repairs (no zone VII presented during this time). Over time, the practice pattern shifted from the Norwich Regimen approach to the RME approach (and with the use of the RME plus [n = 33] and RME only [n = 23] approaches utilized). All approaches yielded similar good to excellent outcomes per total active motion and Miller’s classification, with no tendon ruptures or need for secondary surgery.ConclusionsAn internal audit of practice provided the necessary information regarding implementation to support a shift in hand therapy practice and to gain therapist or surgeon confidence in adopting the RME approach as another option for the rehabilitation of zone IV-VI finger extensor tendon repairs.     

Methods of rehabilitation of fingers after the repair of flexor tendon injuries of first and second degree]

Post-operative rehabilitation of fingers after flexor tendon repair is the important part of therapy which considerably affects final result of the treatment. Method of dynamic traction splinting introduced by Kleinert in 1973, resulted in significantly improvement of final outcomes of repaired flexor tendons, particularly in zone II. Several other than Kleinert dynamic splinting rehabilitation programs were described in the paper. These methods are precisely designed protocols including mode and duration of immobilization of the fingers in the cast, daily range and frequency of finger moves and rate of restoration of the full range of motion. The following rehabilitation protocols were described: active flexion-active extension (Billericay and Belfast), active flexion-active extension using an internal profundus splinting, passive flexion-passive extension and combined regimen of controlled motion with dynamic traction splinting. The late results of the treatment using mentioned above rehabilitation protocols were compared, with respect to proportion of excellent and good results and rate of ruptures of repaired tendons in the course of rehabilitation. Combined regimen of controlled motion with dynamic traction splinting appeared to be superior than other presented methods. There was mentioned that Kleinert dynamic traction splinting, which is the most frequently used post-operative protocol after flexor tendon repairs in Poland, is not the only way of rehabilitation and that other presented methods give comparable results and may be used as an effective, alternative technique.     

Optimizing independent finger flexion with zone V flexor repairs using the Massachusetts General Hospital flexor tenorrhaphy and early protected active motion

PURPOSE: Independent FDS action has been cited to be problematic with repair of multiple tendons in zone V owing to adhesion formation between the flexor digitorum superficialis (FDS) and the flexor digitorum profundus (FDP) tendons. Of the several described flexor repair techniques the ideal tendon repair should be strong enough to allow for early active motion to minimize adhesion formation and maximize tendon healing. Biomechanical studies have proven the Massachusetts General Hospital (MGH) repair to be strong enough to allow for early active motion. The purpose of this study was to examine the use of the MGH technique for zone V flexor tendon injuries to allow for early protected active motion to achieve independent finger flexion through better differential gliding of the tendons. METHODS: We performed a retrospective review 168 zone V finger flexor tendon repairs for 29 patients performed consecutively over 4 years when early active motion was not contraindicated. The same early protected active motion protocol was used for all of these patients. We reviewed total active motion, independent flexion, rupture, and need for tenolysis. These injuries involved 103 FDS and 65 FDP tendons to 103 fingers. The median follow-up period was 24 weeks. Of these 29 patients 19 were men and 10 were women. The average patient age was 28 years. RESULTS: The total active motion for these zone V repairs was 236 degrees +/- 5 degrees Overall 97 of 103 digits attained good to excellent function and 88 of 103 developed some differential glide. One of these patients required a tenolysis. Three repairs ruptured in 1 patient owing to suture breakage that was associated with noncompliance with the dorsal extension block splint. CONCLUSIONS: Our retrospective review of 168 consecutive flexor tendon repairs showed that the MGH technique allowed for early protected active motion, which provided good to excellent functional outcomes with 88 of 103 developing independent finger flexion at an acceptably low complication risk.     

Results of zone II flexor tendon repair in children younger than age 6 years: botulinum toxin type A administration eased cooperation during the rehabilitation and improved outcome

The inability of young children with a zone II flexor tendon repair to cooperate in postoperative care and rehabilitation may represent a high risk for medical and surgical complications. To forestall that risk, botulinum toxin type A (2.5 U/kg, 7 U/kg) injection was used during surgery to induce forearm flexor muscle relaxation in seven children under 6 years old with zone 2 flexor tendon repairs. Patients received a controlled passive motion regimen after surgery. Results were evaluated on the basis of the acquisition of muscle tone and active finger movements, total range of motion of affected joints, postoperative grip strength, muscle atrophy, and phalangeal length. In this prospective clinical study, the mean follow-up was 18 months. All the children had good and excellent results based on the Strickland criteria. As for postoperative complications, one patient had bowstring and another had poor finger sensibility and first web space contracture that required Z-plasty. The selective use of botulinum toxin type A to weaken the targeted muscles generated a sufficient reduction in spontaneous activity of the fingers, permitting an improved rehabilitation program. Botulinum toxin type A administration could be an effective form of therapy, serving as an alternative or adjunct to conventional rehabilitation modalities in these children.     

Friction of the gliding surface. Implications for tendon surgery and rehabilitation.

Finger flexor tendon rehabilitation has come a long way, but further advances are possible. Ideally, a healing tendon should move, but under the minimum load necessary to achieve motion. It is possible to design suture repairs that minimize the friction between tendon and sheath while simultaneously maintaining adequate strength to provide a wide margin of safety during therapy. A looped, four-strand modified Kessler repair is a good example of this type of high-strength, low-friction repair. At the same time, rehabilitation methods can also be optimized. A new modified synergistic motion protocol is described in which wrist flexion and finger extension is alternated with wrist and metacarpophalangeal joint extension and finger interphalangeal joint flexion. Based on evidence from basic science studies, the authors hypothesize that this new protocol will deliver more effective proximal tension on the tendon repair than either passive flexion/active extension or synergistic protocols, and may be useful in patients who are not ready for, or are not reliable with, active motion or place and hold protocols. The scientific basis for these new methods is reviewed, and the concept of the "safe zone" for tendon loading, in which tendon motion occurs without gapping of the repair site, is developed.     

Two-staged tendon reconstruction in flexor tendon ruptures secondary to fracture of the hamate hook

We report a case of 2-staged reconstruction of flexor tendons ruptured spontaneously by attrition. A 49-year-old man presented with inability to flex the ring and little fingers of his left hand. Preoperative computed tomographic scans revealed fracture of the hamate hook. At the time of the operation, both the flexor superficialis and profundus of the little finger and the flexor profundus tendon of the ring finger were ruptured adjacent to the fracture site of the hamate. Because the flexor tendon rupture secondary to the fracture of the hamate is extremely rare, and surgical outcomes of previous reports are not satisfactory, a decision was made to perform 2-staged reconstruction of ruptured flexor tendons. The surgical result was excellent with complete restoration of full range of motion. This report describes for the first time to our knowledge, the technique, and rehabilitation of 2-staged tendon reconstruction in a patient with hook of hamate fracture.     

手Ⅱ区屈肌腱损伤修复及早期康复治疗体会

目的探讨手Ⅱ区屈肌腱损伤修复及早期康复方法及疗效。方法对95例（163指）新鲜的Ⅱ区指屈肌腱损伤采用早期显微修复术,术后早期带支具康复功能锻炼。结果 95例均获随访,时间3-12个月。按TAM法评定疗效：优107指,良40指,中12指,差4指,优良率为90.2%。结论早期显微修复Ⅱ区指屈肌腱损伤,联合应用透明质酸钠,配合术后早期带支具功能锻炼,是减少术后肌腱粘连的有效措施。     

Zone 2 flexor tendon repair in young children: a comparative study of four-strand versus two-strand repair

This study compares the active ranges of finger motion and rupture rates of two-strand and four-strand repairs in zone 2 flexor tendon lacerations in young children. A total of 29 patients (under the age of 4 years) with 32 flexor tendon lacerations in zone 2 were evaluated. The injured tendons were randomly repaired with either two-strand or four-strand modified Strickland techniques. At a mean follow-up period of 11 months, the mean total active motion of interphalangeal joints was 156 degrees in the two-strand and 158 degrees in the four-strand group. According to the Strickland original method, this means an average of 89% (range 57-100%) of normal function in the two-strand and 90% (range 60-100%) in the four-strand group. There were no ruptures of the four-strand repairs, but one two-strand repair failed within 3 weeks of the repair. Statistically, we were not able to show any significant difference in the active ranges of finger motion achieved with two-strand and four-strand repairs.     

Use of a relative motion flexion orthosis after epitendinous zone II flexor tendon repair: A case report

Study designCase reportIntroductionRelative motion flexion (RMF) orthoses are emerging as an option for early active motion (EAM) postoperatively.Purpose of the studyTo describe the rationale and implementation of an RMF orthosis to manage a patient after partial zone II epitendinous flexor tendon repairs.MethodsThis case involves a female who sustained partial flexor tendon lacerations to her middle finger in zone II, 60% flexor digitorum superficialis (FDS) and 90% flexor digitorum profundus (FDP). After epitendinous repair she was referred to therapy for EAM with a no orthosis request. The unusual circumstances prompted the therapist, concerned about the risk of tendon rupture to engage in discussion with the surgeon. Following discussion, a decision was made to use an RMF orthosis for controlled EAM to protect the epitendinous zone II FDS and FDP repairs. Outcomes of range of motion (ROM), total active motion (TAM), %TAM, grip, and quickDASH are reported.ResultsNeither the FDP or FDS tendons ruptured, nor were there any joint contractures. “Good” %TAM outcomes were achieved at 12-week postoperatively. Quick DASH scores improved 61 points indicating a clinically meaningful difference of improved function.DiscussionThe lack of a multi-strand core suture repair is unusual in combination with EAM. The positive outcomes reported in this single patient have raised questions about the protective benefit of the RMF orthosis when used with a zone II epitendinous repair of a 90% FDP laceration. Epitendinous repair of a partial (60%) FDS injury, however, is not uncommon and often not repaired at all.ConclusionsIn this single case report the epitendinous repairs of zone II 90% FDP and 60% FDS with digital nerve involvement were successfully managed with an RMF only orthosis. The use of EAM with an epitendinous repair is in conflict to the current surgical and therapy literature.