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.     

Complications experienced in the rehabilitation of zone I flexor tendon injuries with dynamic traction splinting

A retrospective review of all flexor tendon repairs done between January 1985 to June 1987 determined the complication rate with our method of rehabilitation. One hundred sixty-three flexor tendon lacerations in 83 patients were reviewed. Follow-up ranged from 6 to 42 months. All patients participated in the same 12-week rehabilitation protocol. All patients had passive motion exercises of the interphalangeal joints in the first 2 weeks. We believe that passive stretching of zone I injuries during the first 2 weeks contributed to the zone I complication rate. Of the 20 patients with zone I tendon-to-tendon repairs, 7 patients had significant complications. The 35% complication rate found with zone I injuries has prompted us to modify our postoperative rehabilitation protocol in zone I injuries.     

The aetiology of acute rupture of flexor tendon repairs in zones 1 and 2 of the fingers during early mobilization.

Five hundred and eight patients with 840 acute complete flexor tendon injuries in 605 fingers in zones 1 and 2 underwent surgery and postoperative mobilization in a controlled or early active motion (active flexion-active extension) regimen over a period of 7.5 years. Sixty-eight patients with 79 finger flexor divisions who did not complete the rehabilitation programme were excluded. Of the 440 patients with 728 complete tendon divisions in 526 fingers included in the study, 23 patients ruptured 28 tendon repair(s) in 23 fingers, an overall rupture rate of 4%. One hundred and twenty-nine fingers with zone 1 injuries had a rupture rate of 5%. Three hundred and ninety-seven fingers with zone 2 injuries had a rupture rate of 4%. This study analyses the 23 patients with flexor tendon rupture(s) to identify causative factors. In approximately half of these patients, tendon rupture followed acts of stupidity. The implications of this are discussed. There was no significant relationship between tendon rupture and the age or sex of the patients, smoking or delay between injury and tendon repair and there was no particular prevalence of zone 2C level injuries among the fingers in which tendon rupture occurred.     

Factors that influence the outcome of zone I and zone II flexor tendon repairs in children

PURPOSE: To evaluate the factors that influenced the clinical results of zone I and II flexor tendon repairs in children at a single institution. METHODS: Forty-one fingers (35 patients) in patients ages 2 to 14 years with zone I or II flexor tendon injuries were identified. There was a zone I tendon injury in 16 fingers and a zone II tendon injury in 25 fingers. Concomitant injuries to the digital nerves were seen in 18 fingers. Primary repair was performed within 1 week in 35 fingers and delayed repair (2-9 wk) was performed in 6 fingers. After surgery 22 fingers (21 patients) were treated with early controlled mobilization and 19 fingers (14 patients) were treated with plaster immobilization. RESULTS: All patients were available for evaluation at a mean follow-up period of 42 months. Patients were subdivided into 2 age groups: (1) 0 to 7 years and (2) 8 to 15 years. Digital performance was evaluated by determining the percentage return of normal finger function according to a total active motion formula. Functional evaluation of all digits in both groups showed excellent or good results. Zone I repairs had better results than zone II repairs and isolated tendon repairs had better results than those with associated nerve repairs. The age of the patients nor postoperative protocol did not influence the final digital motion. CONCLUSIONS: A good outcome can be expected after repair of zone I or II flexor tendon injuries in children. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic III.     

Botulinum Toxin Use as an Adjunctive Modality in a Patient with Multiple Flexor Tendon Ruptures

Botulinum toxin A has been described in treatment protocols for several disease processes, from primary axillary hyperhydorosis to esophageal dysfunction. It is best known for its use in plastic and dermatological practices. Botulinum toxin has a straightforward mechanism of action. The toxin inhibits acetylcholine release at the neuromuscular junction causing a chemical denervation, which ceases contractions of the muscle. With its minimal side effect profile, botulinum toxin should be considered when muscle spasm is a detriment. This case involves an injury to the hand of a patient with a history of intermittent diffuse muscle spasms. Subsequently, due to the patient's previous upper extremity muscle spasms, repeated flexor tendon repair ruptures of the index finger occurred until botulinum toxin was administered to the offending muscle. The patient has not required any additional surgical interventions for the repaired tendon and is now actively flexing all digits. This case report demonstrates how botulinum toxin can be used in a clinical scenario when decreased muscle activity is desired to promote tendon healing.     

Complications after treatment of flexor tendon injuries

The goals of flexor tendon repair are to promote intrinsic tendon healing and minimize extrinsic scarring in order to optimize tendon gliding and range of motion. Despite advances in the materials and methods used in surgical repair and postoperative rehabilitation, complications following flexor tendon injuries continue to occur, even in patients treated by experienced surgeons and therapists. The most common complication is adhesion formation, which limits active range of motion. Other complications include joint contracture, tendon rupture, triggering, and pulley failure with tendon bowstringing. Less common problems include quadriga, swan-neck deformity, and lumbrical plus deformity. Meticulous surgical technique and early postoperative tendon mobilization in a well-supervised therapy program can minimize the frequency and severity of these complications. Prompt recognition of problems and treatment with hand therapy, splinting, and/or surgery may help minimize recovery time and improve function. In the future, the use of novel biologic modulators of healing may nearly eliminate complications associated with flexor tendon injuries.     

Finger flexor tendon forces are a complex function of finger joint motions and fingertip forces.

In vivo tendon forces provide a view inside the musculoskeletal system revealing muscle function and potential injury etiologies. The studies presented here measured the in vivo tendon force of the flexor digitorum superficialis of the long finger during open carpal tunnel release surgery in ten adult patients. Forces were measured during passive movement of the finger, isometric pinch, and dynamic tapping of the finger. The tendon forces during passive movement of the finger were the largest with the finger fully extended. During isometric pinch, tendon force was linearly related to fingertip force, and was on average 3.3 times larger than the fingertip force. During dynamic activities, however, the relationship between tip and tendon force was nonlinear and often remained elevated when the finger was moving but with no applied force. Tendon forces were the highest with the isometric finger pinch. In conclusion, tendon force is a completed function of both fingertip load and motion of the joints that the tendons cross. A comparison of these results with others published in the literature indicated that rehabilitation processes need to incorporate a systems approach rather than rely on one specific physiologic relationship to minimize finger flexor tendon forces.     

Rehabilitation of flexor and extensor tendon injuries in the hand: Current updates

In recent years, a significant amount of research in the field of tendon injury in the hand has contributed to advances in both surgical and rehabilitation techniques. The introduction of early motion has improved tendon healing, reduced complications, and enhanced final outcomes. There is overwhelming evidence to show that carefully devised rehabilitation programs are critical to achieving favourable outcomes. Whatever the type, or level, of flexor or extensor injury, the ultimate goal of both the surgeon and therapist is to protect the repair, modify peritendinous adhesions, promote optimal tendon excursion and preserve joint motion. Early tendon motion regimens are initiated at surgery or within 5 days post repair. Intra-operative information from the surgeon to the therapist is vital to the choice of splint protected position to reduce repair rupture/gap forces, and to commencement of active, or splint controlled, motion for tendon excursion. Decisions should align with the phases of healing, the clinician's observations, frequent range of motion measurements and patient input. Clinical concepts pertinent to early motion rehabilitation decisions are presented by zone of injury for both flexor and extensor tendons during the early phases of healing.     

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.     

Effect of synergistic wrist motion on adhesion formation after repair of partial flexor digitorum profundus tendon lacerations in a canine model in vivo.

BACKGROUND: Therapy employing passive finger flexion and active finger extension with the wrist fixed in flexion is commonly used after flexor tendon repair. However, this method of rehabilitation may not produce full tendon excursion because of buckling of the tendon within its sheath with passive flexion. Studies of cadavera suggest that the use of synergistic wrist and finger motion may improve tendon gliding. The purpose of this study was to assess the effects of passive digital motion, performed with either wrist fixation or synergistic wrist motion, on adhesion and gap formation after flexor tendon repair. METHODS: Sixty-six dogs were randomly allocated to two groups. In each group, two flexor digitorum profundus tendons of one forepaw were partially (80%) lacerated and then repaired with a modified Kessler suture. In each group, a different postoperative therapy (wrist fixation or synergistic motion) was performed twice daily. The dogs were killed at one week, three weeks, or six weeks after surgery, and the repaired tendons were evaluated to determine the adhesion grade and adhesion breaking strength. RESULTS: The synergistic motion group had a significantly lower adhesion grade and significantly less adhesion breaking strength than the wrist fixation group at three and six weeks (p < 0.05). At one week, there was no significant difference between the two therapy groups (p > 0.05). CONCLUSIONS: Passive digital flexion and extension with synergistic wrist motion was an effective therapy after repair of partial zone-2 lacerations in a canine model.     

In vivo flexor tendon forces increase with finger and wrist flexion during active finger flexion and extension.

The effects of different hand motions and positions used during early protected motion rehabilitation on tendon forces are not well understood. The goal of this study was to determine in vivo forces in human flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons of the index finger during active unresisted finger flexion and extension. During open carpal tunnel surgery (n = 12), flexor tendon forces were acquired with buckle force transducers, and finger positions were recorded on video while subjects actively flexed and extended the fingers at two different wrist angles. Mean in vivo FDP tendon forces varied between 1.3N +/- 0.9 N and 4.0 N +/- 2.9 N while mean FDS tendon forces ranged from 1.3N +/- 0.5 N to 8.5 N +/- 10.7 N. FDP force increased with active finger flexion at both wrist angles of 0 degrees or 30 degrees flexion. FDS force increased with finger flexion when the wrist was in 30 degrees flexion, but was unchanged when the wrist was in 0 degrees of flexion. Tendon forces were similar regardless of whether the fingers were moving in the flexion or extension direction. Active finger flexion and extension with the wrist at 0 degrees and 30 degrees flexion may be used during early rehabilitation protocols with limited risk of repair rupture. This risk can be further decreased for a FDS tendon repair by reducing wrist flexion angle.     

Effect of synergistic motion on flexor digitorum profundus tendon excursion

Clinical and experimental studies have shown that postoperative rehabilitation is an important factor that improves digital function after flexor tendon repair. In the current study, the effect of synergistic wrist and finger motion therapy and fixed flexed wrist motion therapy on the in vivo gliding excursion was evaluated after repair of partial laceration of the canine flexor digitorum profundus tendon. The gliding excursion of the repaired tendons treated with synergistic wrist and finger motion therapy was significantly greater than that of tendons rehabilitated with the wrist fixation therapy, suggesting that wrist extension generates force that can pull the repair site through the pulley, thereby increasing passive excursion of the tendon. As a result of increased tendon excursion, synergistic therapy may improve the clinical outcome after repair of partial tendon lacerations.     

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.     

Clinical outcomes associated with flexor tendon repair

Review of the outcomes of clinical flexor tendon repairs reported over the past 15 years showed advances in the outcomes with excellent or good functional return in more than three fourths of primary tendon repairs following a variety of postoperative passive/active mobilization treatments. Strickland and Glogovac criteria are the most commonly adopted methods to assess function. Repair ruptures (4%-10% for zone II finger flexors and 3%-17% for the FPL tendon), adhesion formations, and stiffness of finger joints remain frustrating problems in flexor tendon repairs and rehabilitation. Four approaches are suggested to improve outcomes of the repairs and to solve these difficult problems,which include stronger surgical repairs, appropriate pulleys or sheath management, optimization of rehabilitation regimens, and modern biologic approaches.     

Flexor tendon injuries in pediatric patients

PURPOSE: The purpose of this research was to study the incidence and outcome of flexor tendon injuries in pediatric patients. METHODS: A survey of flexor tendon repair in children less than 16 years of age was performed in the City of Helsinki during 2000-2005. A retrospective clinical outcome study of all consecutive 28 patients with 45 involved fingers treated in Children's Hospital was also performed at a mean 38 months (range 12-53 months) after surgery. Active motion program after multistrand tendon repair was used in 33 fingers, cast immobilization in 11 fingers, and elastic bands in 1 finger. Functional and cosmetic subjective result was evaluated by a visual analog scale (VAS, 0-100). Range of motion (ROM) of metacarpophalangeal (MCP) and interphalangeal (IP) joints were measured. Grip strength was recorded. Functional outcome methods of Buck-Gramcko, ASSH, Strickland, and distal interphalangeal joint (DIP) ROM methods were applied. RESULTS: The calculated annual incidence of finger flexor injury per child in Helsinki was 0.036 per 1000. There were no ruptures of the multistrand repairs with active motion program, but three 2-strand core sutures failed within 1 month of the repair. Mean functional and cosmetic VAS scores (all 28 patients) were 87 and 84. Mean ROM ratio of the DIP joint in zone 1 and 2 injuries was 60%, compared to 98% in zone 3 and 5 injuries. Ranges of motion of the proximal interphalangeal (PIP) and MCP joints were practically normal in all patients. There was a discrepancy among the functional outcome scores, with good and excellent results in all 45 fingers (Buck-Gramcko), in 39 fingers (ASSH), in 36 fingers (original Strickland), and in 32 fingers (DIP ROM). CONCLUSIONS: Flexor tendon injuries in children are rare. Both subjective and objective outcomes are generally good. Active motion program is an effective technique after multistrand flexor tendon repair at all levels in children. Range of motion of the DIP joint may be a more effective means of evaluating outcome in pediatric flexor tendon injuries. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.     

Pediatric flexor tendon injuries: A 10-year outcome analysis

BACKGROUND:

Primary flexor tendon repair was first introduced in the 1960s. Since then, major advances in the understanding of flexor tendon anatomy and biology have led to improved outcomes following repair. Relative to the adult population, sparse knowledge exists as to which operative and postoperative treatments are most successful in children. This is due, in part, to the rarity of pediatric tendon lacerations compared with the adult population, but also related to challenges when working with smaller anatomy and the decreased compliance in children with respect to rehabilitation protocols. Published reports indicate that the incidence of ‘good’ flexor tendon repair outcomes is as low as 53%.

OBJECTIVE:

To determine the injury pattern and demographics of pediatric flexor tendon injuries involving zones I, II and III over the past decade, and to report results and identify treatment paradigms that are associated with optimal outcomes.

METHODS:

A retrospective chart review of all flexor tendon injuries involving zones I, II and III between April 2001 and December 2010 was performed. Parameters reviewed included demographics, injury mechanism, repair technique, outcomes and complications.

RESULTS:

A total of 47 patients with a median age of eight years experienced 100 tendon injuries. The most common cause of injury was glass (n=22), with the most common digit injured being the small finger (n=30). Tendon injuries included the following: flexor digitorum superficialis (n=46); flexor digitorum profundus (n=45), flexor pollicis longus (n=8); and adductor pollicis longus (n=1). Zone III had the highest number of injuries (n=47), followed by zone II (n=39). Ninety tendons were repaired using polyester suture, the most common size being 4-0. The modified Kessler technique was used in the majority of cases (n=62). Only 22 tendons underwent an epitendinous repair. Splint immobilization was used in 30 patients and a full cast in 17. The median duration of immobilization was four weeks. Forty-two patients underwent postoperative hand therapy. Using the American Society for Surgery of the Hand Total Active Motion (TAM) score, 40 of 47 patients experienced 100% recovery with no functional limitations. Two patients had a score <100%, not necessitating further surgery. A second operation was required for five patients. All patients in this group demonstrated 100% TAM at one year.

CONCLUSION:

Pediatric flexor tendon injuries remain rare and usually involve the dominant hand holding or manipulating an object. An excellent outcome was found in 95.9% of patients assessed by TAM scores. Repair technique was chosen according to the size of tendon involved. Patients not treated with hand therapy and not immobilized in a cast were often too young to participate in rehabilitation. Based on the results, immobilization of young children for four weeks is safe and does not worsen functional outcomes. Of the patients requiring a second procedure, no predictive variables for poorer outcomes were found on analysis of age, outcome, cause, location, repair technique, rehabilitation protocol or zone of injury.     

早期康复治疗在Ⅱ～Ⅴ区指屈肌腱损伤术后的临床应用

目的：报道指屈肌腱修复后早期康复介入的疗效。方法对73例Ⅱ～Ⅴ区指深屈肌腱损伤患者,随机分为观察组37例和对照组36例,两组患者性别、年龄、致伤原因、损伤指别、神经损伤比较,差异均无统计学意义（P＞0.05）,具有可比性。对照组给予临床常规治疗,术后4周再行康复治疗;观察组在急诊修复后第4天即在使用支具情况下开始进行物理治疗及康复训练。两组采用相似康复治疗方法,应用手指总主动活动度（TAM）测定法评定疗效。结果术后3--6个月,按TAM法评定患指功能,观察组优良率明显高于对照组（P〈0.01）,活动度及手指感觉、两点辨别觉均优于对照组,差异有统计学意义（P＜0.05）。结论指屈肌腱修复术后功能锻炼开始的时间愈早,手功能恢复的优良率愈高。     

Zone I flexor profundus tendon repair in children 5-10 years of age using 3 "figure of eight" sutures followed by immediate active mobilization

A review of the English medical literature over the last 20 years reporting on flexor profundus lacerations revealed only 55 reported cases of zone I flexor profundus lacerations in children. The standard repair technique in young children (5-10 years of age) has been either tendon reinsertion into bone (usually Bunnell technique) for distal zone I injuries or a 2-strand repair (usually modified Kessler technique) for proximal zone I injuries. We report on 22 children (5-10 years of age) with zone I flexor profundus tendon lacerations (10 children had distal zone I injury and 12 had proximal zone I injury) repaired with a 6-strand technique (3 separate "figure of 8" sutures) followed by early postoperative active mobilization. There were no ruptures. Using the Strickland and Glogovac criteria (on the basis of the net active motion of both the interphalangeal joints), all children qualified for an excellent outcome. However, using Moremen and Elliot criteria (on the basis of the net active motion of the distal interphalangeal joint only), 11 children had an excellent outcome, 3 had a good outcome, and 8 had a fair outcome. Our results were compared with previously reported series. It was concluded that the 6-strand figure of 8 suture technique may be used in pediatric zone I injuries and it is strong enough to allow safe early postoperative active mobilization in the 5- to 10-year age group children.     

Comparison of pullout button versus suture anchor for zone I flexor tendon repair

PURPOSE: To evaluate the clinical outcome after repair of zone I flexor tendon injuries using either the pullout button technique or suture anchors placed in the distal phalanx. METHODS: Between 1998 and 2002 we treated 26 consecutive zone I flexor tendon injuries. Thirteen patients had repairs from 1998 to 2000 using a modified pullout button technique (group A) and 13 patients had repair using suture anchors placed in the distal phalanx (group B). Patient characteristics were similar for both groups. The same postoperative flexor tendon rehabilitation protocol and follow-up schedule were used for both groups. Evaluation included range of motion, sensibility and grip strength, failure, complications, and return to work. The Student t test was used to determine significant differences. RESULTS: All patients completed 1 year of follow-up evaluation. There were 2 infections in group A that resolved with oral antibiotics and no infections in group B. There were no tendon repair failures and no repeat surgeries in either group. At final follow-up evaluation there were no statistically significant differences for the following end points: sensibility (Semmes-Weinstein monofilament testing and 2-point discrimination), active range of motion (at the proximal interphalangeal joint, distal interphalangeal joint, or their combined motion), flexion contracture (at the proximal interphalangeal joint, distal interphalangeal joint, or their combined contracture), and grip strength (injured tendon as a percent of the contralateral uninjured tendon). The suture anchor group had a statistically significant improvement for time to return to work. CONCLUSIONS: There was no significant difference in the clinical outcome after flexor tendon repair using either suture anchors or the pullout button technique. A significant improvement was found for time to return to work for repairs using the suture anchor technique. Flexor tendon repair can be achieved using suture anchors placed in the distal phalanx, thereby avoiding the potential morbidity associated with the pullout button technique. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level III.     

Comparison of surgical trends in zone 2 flexor tendon repair between Turkish and international surgeons

ObjectivesThe aim of this study was to evaluate Turkish trends in zone 2 flexor repair with regards to surgical technique, suture materials, anesthesia and post-operative rehabilitation and compare this with international surgeons by modifying Gibson's survey.MethodsA printed and online survey consisting of 19 questions modified from Gibson's survey was sent to 590 Turkish and international surgeons. The surgeon's years in practice, province of practice, residency type, number of zone 2 flexor tendon repairs done in a year, preferred surgical technique, suture material, complications and postoperative protocols were asked to the respondents.ResultsA total of 194 surgeons completed the survey (a 25% response rate). Of those who completed the survey, 91 were international (mostly from far eastern countries) and 103 were Turkish surgeons. Years in practice and educational background had influence on the decision-making. There were differences between the Turkish and international surgeons in the core and epitendinous suture thickness preference and flexor tendon sheath repair. There was a statistically significant relationship between the province of practice and the use of WALANT (Wide awake local anesthesia no tourniquet) (p < 0.05). While the majority of respondents who preferred postoperative early passive motion protocol were from Turkey (61.5%), the majority of respondents who preferred early active motion protocol were practicing abroad (73.9%).ConclusionDespite some variations the surgeons involved in this study follow to a large extent the current literature.