The Learning Curves of Adelaide- and Gan-Modified Lim-Tsai Flexor Tendon Repair Techniques.

PURPOSE: Surgical performance that improves with experience is often depicted as representing a "learning curve." Although numerous studies examine the tensile properties of various flexor tendon repairs, few compare the associated learning curves. This study aims to address this gap by comparing the learning curves of Adelaide- and Gan-modified Lim-Tsai repairs. Emphasizing the difference in learning curves is crucial because it highlights the tension between achieving biomechanically superior repairs, which may be challenging to many surgeons, and opting for possibly incrementally less strong but more feasible techniques. METHODS: We organized a workshop attended by 20 medical students whose experience in surgery was limited to a few suturing exercises. Each participant repaired five porcine tendons in situ either with Adelaide- or Gan-modified Lim-Tsai, followed by a peripheral suture. We tested all tendons with linear static testing to measure ultimate and yield loads. In addition, repair times were recorded for each repair. We used a linear mixed model to compare learning between the techniques. RESULTS: Ultimate loads increased with experience and were higher in Adelaide technique during the first two repairs, compared with Gan-modified Lim-Tsai (80 N vs 63 N and 79 N vs 66 N, respectively). Yield loads also increased with experience but did not differ between the repair techniques at any time point. Mean repair times decreased from 44 to 28 minutes and from 46 to 25 minutes with Adelaide- and Gan-modified Lim-Tsai repairs, respectively. CONCLUSIONS: The Adelaide core suture had a higher initial ultimate load capacity despite fewer suture strands, possibly indicating better tension consistency. The ultimate load of the Gan-modified Lim-Tsai repair increased between the first and fifth repair, and repeats were needed to achieve comparable results with the Adelaide repair. CLINICAL RELEVANCE: The results of this study suggest that both repair methods are suitable for novice surgeons, but Adelaide tends to result in higher strength from the first repair. Generalizability to other repairs should be made with caution.

Passive Mobilization With Place-and-Hold Versus Active Mobilization Therapy After Flexor Tendon Repair: 5-Year Minimum Follow-Up of a Randomized Controlled Trial.

PURPOSE: There is no consensus on the optimal postoperative rehabilitation program following flexor tendon repair. Some studies suggest a faster recovery after active mobilization, whereas other studies have failed to find any differences between active and passive mobilization at 12 months. To our knowledge, no prior randomized controlled trial has compared the long-term effects of these two approaches. This randomized controlled trial compared the long-term outcomes of active mobilization with those of passive mobilization in combination with place-and-hold. METHODS: Sixty-four patients with a flexor tendon injury in zones I or II were included in the study. After surgery, patients were randomized to either active mobilization or passive mobilization with place-and-hold. Forty-seven patients were available for the 5-year minimum follow-up. Assessments included range of motion, grip strength, key pinch, as well as the Disabilities of the Arm, Shoulder, and Hand (DASH) and ABILHAND questionnaires. RESULTS: At the 5-year minimum follow-up, range of motion was significantly better in the group treated with passive mobilization with place-and-hold compared with the active mobilization group. Furthermore, there was a significant deterioration in the range of motion and an increased flexion contracture in the active mobilization group compared with 1 year after surgery. Grip strength deteriorated significantly in both groups from the 1-year to the 5-year minimum follow-up, but key pinch did not change. In both groups, DASH and ABILHAND scores improved from the 1-year to the 5-year minimum follow-up. CONCLUSIONS: Passive mobilization with place-and-hold following flexor tendon repair results in superior long-term outcomes compared with active mobilization. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.

Which is more effective? Porcine tendon or 3D- printed flexor tendon? A study of model realism and educational utility in a flexor tendon repair workshop.

Introduction: Animal models in orthopaedic surgical training have raised concerns about ethics and availability, prompting the search for non-animal alternatives. The 3D-printed silicone tendon model has emerged as a potential alternative due to its hygiene and reusability. This study aimed to compare the effectiveness of the two models for flexor tendon repair training. Materials and methods: A survey involved 25 postgraduate trainees with no prior experience in flexor tendon repair. Porcine tendon models and 3D-printed models were used, with participants evaluating accuracy, understanding of pulley systems, joint flexion, tissue feel, and model realism. Repairs were evaluated by experienced surgeons, and participants completed a survey. Results: Both models demonstrated satisfactory accuracy and realistic joint flexion. The porcine model scored higher in anatomical accuracy, while the 3D-printed model excelled in understanding pulley systems. The porcine model provided realistic tissue feel, while the 3D-printed model facilitated anatomy teaching. No significant difference was found in educational utility. The 3D-model was perceived as hygienic and odourless, whereas the porcine model offered better tendon handling. The 3D-model improved visualization of suture placement. Both models were equally accepted and recommended for training. Conclusion: The 3D-printed silicone tendon model is a cost-effective and reproducible alternative to porcine models in flexor tendon repair training. Although the 3D-printed model has limitations in mimicking human tendons, it was equally effective in teaching suturing techniques and improving repair skills. Combining the porcine model and 3D-printed model provides a comprehensive approach to flexor tendon repair training, addressing the limitations of each model and enhancing the educational experience.

Outcomes of Zone II Flexor Tendon Repair Under General Versus Wide Awake Local Anesthesia: A Randomized Controlled Trial.

PURPOSE: Wide awake local anesthesia no tourniquet (WALANT) is gaining popularity with flexor tendon repair. We hypothesized that results of zone II flexor tendon repair performed under WALANT would be superior to those performed under general anesthesia (GA). METHODS: A randomized controlled trial was conducted to compare results of repair of zone II flexor tendon lacerations under WALANT versus GA. Following sample size estimation, 86 digits were included and randomized into two groups. All surgeries were performed by a single surgeon using a six-stranded core stitch and running epitenon suture. All patients followed the same early active rehabilitation protocol. The primary outcome was recovery calculated using the Strickland and Glogovac criteria. Secondary outcomes included rupture rate, complication rate, and Disabilities of the Arm, Shoulder, and Hand (DASH) score. All outcomes were reported at the 6-month visit for all patients. RESULTS: Of the 86 digits, three were lost to follow-up. Analysis was performed on 43 digits in the WALANT group and 40 in the GA group. Demographic characteristics including age and sex were comparable in both groups. Rupture of the repair occurred in two digits in each of the WALANT and GA groups. An excellent or good outcome was achieved in 49% and 56% of the digits in the WALANT and GA groups, respectively. This difference was not statistically significant. DASH scores averaged 12.9 and 8.4 for the WALANT and GA groups, respectively. CONCLUSIONS: WALANT may not be superior to GA in regards function, rates of rupture, and patient-reported outcomes in repair of zone II flexor tendon lacerations. Surgeons can be confident in choosing either technique if rigorous patient selection, sound surgical technique, and proper hand therapy are employed. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.

Biomechanical Analysis of a New Odd-Numbered Strand Suture Technique for Early Active Mobilization After Primary Flexor Tendon Repair.

Purpose: The placement of multistrand sutures during flexor tendon repair is complex and challenging. We developed a new, simpler, nine-strand suture, which we term the Tajima nines. The Tajima nines repair method is a new odd-numbered strand tendon technique. Methods: Fourteen porcine flexor tendons were transected and repaired using the Tajima nines repair method, without placement of peripheral sutures. This technique is a modification of the Lim and Tsai repair method; it uses a 4-0 monofilament nylon, 3-strand line, and two needles. The repaired tendons were tested for linear, noncyclic, load-to-failure tensile strength. The initial gap, 2-mm gap-formation force, and ultimate strength were measured. Results: The initial gap-formation force was 27.9 ± 7.5 newtons (N), the 2-mm gap-formation force was 39.2 ± 4.7 N, and the ultimate strength was 76.7 ± 17.2 N. Eight, three, and three of the 14 tendons repaired using the Tajima nines method demonstrated failure because of thread breakage, knot failure, and suture pull-out, respectively. Conclusions: This biomechanical study demonstrated that Tajima nines repair was associated with particularly high initial tension at the repair site; there were minor variations in the initial load and 2-mm gap-formation load. Our results suggest that Tajima nines repair with peripheral suturing allows the repaired flexor tendon to tolerate the stresses encountered during early active mobilization. Clinical relevance: This simple nine-strand technique will be particularly useful for inexperienced surgeons who perform early active mobilization after primary flexor tendon repair because the technique is a modification of the Lim and Tsai repair method using a triple strand instead of a double strand.

Mental and behavioural disorders increase the risk of tendon rupture after flexor tendon repair in zone I and II.

Introduction: The effect of mental and behavioural disorders (MBD) on the risk of tendon ruptures after flexor tendon repair is not well understood. This study aimed to analyse the association between MBD and tendon rupture after flexor tendon repair in zones I and II. Methods: Data from the Swedish National Registry for Hand Surgery (HAKIR) on patients with a complete flexor tendon repair at our department between 2012 and 2019 were followed for a minimum of 2 years to assess the rate of rupture. Independent variables were collected from HAKIR and clinical records: prevalence MBD based on ICD-10 codes F0-F99, age, sex, injured tendon, number of injured fingers, day to surgery, core suture, digital nerve injury, smoking, injury mechanism, and rehabilitation method. Multiple logistic regression was used to assess the association between variables. Results: A cohort of 593 patients with 49 ruptures (8.2%) was identified. Potential causes of rupture were non-adherence behaviour in 16 (33%), accidents in seven (14%), infections in six (12%), and no clear cause in 20 (41%) patients. Patients with MBD had an association to rupture (OR 3.6), 17.7% ruptures compared to 7.2% in patients with no diagnosed disorders. Patients >50 years of age had a higher risk compared to patients <25 years (OR 4.3), 15% compared to 3.9%' respectively. Men had a higher risk compared to women (OR 2.9), 10% compared to 4.3%' respectively. Conclusion: We identified an association between the prevalence of mental and behavioural disorders and rupture after flexor tendon repair.

A Simple Technique Ensuring Adequate Exposure During Primary Repair of Complex Thumb Injuries.

As the thumb is pronated, primary repair of complex injuries may be more difficult than the repair of other digits. We describe a simple technique that facilitates thumb repair. We insert a Kirschner wire perpendicular to the bone axis in the middle of the proximal phalanx, which ensures adequate exposure of the palmar aspect without the need for thumb position adjustment by an assistant. This technique is particularly useful when inexperienced surgeons perform thumb replantation and primary flexor tendon repair using a multistrand suture technique.

Pentamidine-loaded gelatin decreases adhesion formation of flexor tendon.

Background: Prevention of adhesion formation following flexor tendon repair is essential for restoration of normal finger function. Although many medications have been studied in the experimental setting to prevent adhesions, clinical application is limited due to the complexity of application and delivery in clinical translation. Methods: In this study, optimal dosages of gelatin and pentamidine were validated by gelatin concentration test. Following cell viability, cell migration, live and dead cell, and cell adhesion assay of the Turkey tenocytes, a model of Turkey tendon repair was established to evaluate the effectiveness of the Pentamidine-Gelatin sheet. Results: Pentamidine carried with gelatin, a Food and drug administration (FDA) approved material for drug delivery, showed good dynamic release, biocompatibility, and degradation. The optimal dose of pentamidine (25ug) was determined in the in vivo study using tenocyte viability, migration, and cell adhesion assays. Further biochemical analyses demonstrated that this positive effect may be due to pentamidine downregulating the Wnt signaling pathway without affecting collagen expression. Conclusions: We tested a FDA-approved antibiotic, pentamidine, for reducing adhesion formation after flexor tendon repair in both in vitro and in vivo using a novel turkey animal model. Compared with the non-pentamidine treatment group, pentamidine treated turkeys had significantly reduced adhesions and improved digit function after six weeks of tendon healing. The translational potential of this article: This study for the first time showed that a common clinical drug, pentamidine, has a potential for clinical application to reduce tendon adhesions and improve tendon gliding function without interfering with tendon healing.

The value of local dexmedetomidine as an adjuvant to ultrasound-guided wide awake local anesthesia no tourniquet (WALANT) in flexor tendon repair surgeries: a randomized controlled trial.

BACKGROUND: The Wide-Awake Local Anesthesia No Tourniquet (WALANT) technique allows intraoperative motor assessment of tendon repair integrity of the hand compared with general anesthesia or brachial plexus block. No studies have tested the effect of adding dexmedetomidine to lidocaine on the analgesic properties of the WALANT technique, which is the aim of our study. METHODS: A total of 128 patients aged more than 18 years were scheduled for surgical flexor tendon injury repair using WALANT technique. Patients were divided into two equal groups. Ultrasound-guided subcutaneous injection of lidocaine 1% with dexmedetomidine (1 µg/kg), Group D, or without dexmedetomidine, Group C, was performed at four points: proximal to the wrist joint, the distal forearm, palm region, and proximal phalanges. The primary outcome was total morphine consumption throughout the first postoperative day. Secondary outcomes included number of patients requiring rescue analgesia, time to first analgesic request, and pain score. RESULTS: Total morphine consumption was significantly (P < 0.001) lower in group D (2.66 ± 0.998) than in group C (3.66 ± 1.144) mg. Number of patients requiring rescue analgesia was significantly (P < 0.001) lower in group D (54.7% (35)) than group C (100.0% (64)). The time for first request for analgesia was significantly (P < 0.001) longer in group D (11.31 ± 6.944) than in group C (5.91 ± 4.839) h. Pain score was significantly higher in group C than D at three (P < 0.001), and six (P = 0.001) hours (P = 0.001) postoperatively. CONCLUSION: Dexmedetomidine significantly improves the analgesic quality of WALANT when added to lidocaine with less opioid consumption. TRIAL REGISTRATION: (ID: PACTR202203906027106; Date: 31/07/2023).

Flexor Injury Rehabilitation Splint Trial (FIRST): protocol for a pragmatic randomised controlled trial comparing three splints for finger flexor tendon repairs.

BACKGROUND: Without surgical repair, flexor tendon injuries do not heal and patients' ability to bend fingers and grip objects is impaired. However, flexor tendon repair surgery also requires optimal rehabilitation. There are currently three custom-made splints used in the rehabilitation of zone I/II flexor tendon repairs, each with different assumed harm/benefit profiles: the dorsal forearm and hand-based splint (long), the Manchester short splint (short), and the relative motion flexion splint (mini). There is, however, no robust evidence as to which splint, if any, is most clinical or cost effective. The Flexor Injury Rehabilitation Splint Trial (FIRST) was designed to address this evidence gap. METHODS: FIRST is a parallel group, superiority, analyst-blind, multi-centre, individual participant-randomised controlled trial. Participants will be assigned 1:1:1 to receive either the long, short, or mini splint. We aim to recruit 429 participants undergoing rehabilitation following zone I/II flexor tendon repair surgery. Potential participants will initially be identified prior to surgery, in NHS hand clinics across the UK, and consented and randomised at their splint fitting appointment post-surgery. The primary outcome will be the mean post-randomisation score on the patient-reported wrist and hand evaluation measure (PRWHE), assessed at 6, 12, 26, and 52 weeks post randomisation. Secondary outcome measures include blinded grip strength and active range of movement (AROM) assessments, adverse events, adherence to the splinting protocol (measured via temperature sensors inserted into the splints), quality of life assessment, and further patient-reported outcomes. An economic evaluation will assess the cost-effectiveness of each splint, and a qualitative sub-study will evaluate participants' preferences for, and experiences of wearing, the splints. Furthermore, a mediation analysis will determine the relationship between patient preferences, splint adherence, and splint effectiveness. DISCUSSION: FIRST will compare the three splints with respect to clinical efficacy, complications, quality of life and cost-effectiveness. FIRST is a pragmatic trial which will recruit from 26 NHS sites to allow findings to be generalisable to current clinical practice in the UK. It will also provide significant insights into patient experiences of splint wear and how adherence to splinting may impact outcomes. TRIAL REGISTRATION: ISRCTN: 10236011.

Comparison of pulley plasty, pulley venting and resection of flexor digitorum superficialis slip after zone II flexor tendon repair: a cadaver study.

LEVEL OF EVIDENCE: V.

Cyclic testing of six-strand suture techniques for zone 2 flexor tendon lacerations.

BACKGROUND: Biomechanical analysis using cyclic testing for repaired flexor tendons is a clinically relevant method. The aim of this study was to evaluate the tensile properties of two six-strand suture techniques, the triple looped suture and Yoshizu #1 suture techniques using cyclic testing under simulating early active mobilization conditions. METHODS: Twenty-five flexor digitorum profundus tendons harvested from fresh frozen human cadaver hands were repaired in zone 2 utilizing one of three repair techniques: the 2-strand modified Kessler (MK) technique as a control, the triple looped suture (TLS) and Yoshizu #1 suture (Y1) techniques. In each suture technique, 4-0 monofilament nylon sutures were used for core sutures and 6-0 monofilament nylon sutures for circumferential running sutures. Cyclic testing was performed using 20 N with 600 cycles at 1 Hz. RESULTS: Five out of eight specimens in the MK group ruptured during cyclic testing. Thus, this group was excluded from analysis. On the other hand, all tendons in the TLS and Y1 groups tolerated cyclic testing. Average gaps of the TLS and Y1 groups were 0.5 ± 0.8 mm and 1.9 ± 2.2 mm, respectively. All tendons in the TLS group and six out of nine tendons in the Y1 group formed gaps less than 2 mm. Two tendons in the Y1 group formed a gap of 3.8 and 6.6 mm had breakage of peripheral sutures at the first cycle. Mean ultimate tensile force of the TLS and Y1 group measured after cyclic tensing, were 66.2 ± 9.0 N and 65.9 ± 13.1 N, respectively. No statistical difference between the two groups was found in gap and ultimate tensile forces. CONCLUSIONS: This study suggested that the TLS and Y1 techniques have tensile properties to allow early active mobilization. None of tendons repaired with the TLS technique had gaps more than 2 mm.

Relationship between pain, nerve injury and clinical outcomes after flexor tendon injuries in zones 1-2: a retrospective cohort study.

Introduction: The influence of pain and a concomitant digital nerve injury on the course of rehabilitation after flexor tendon injury remains ambiguous. The objectives of the study were to: i) analyse the evolution of pain spanning one year after a primary flexor tendon repair in zones 1-3; ii) examine the differences in pain levels in patients with and without digital nerve injury; and iii) evaluate the relationship between pain, digital nerve injury and pain medication, total active motion (TAM), DASH scores and patient satisfaction. Methods: Data from 189 patients were retrieved from a flexor tendon registry between 2014 and 2020. Differences in pain, TAM, DASH and patient satisfaction were analysed. Multiple linear and binary logistic regression analyses were performed to determine the relationship between clinical outcomes. Results: Pain significantly decreased in the course of rehabilitation (p < 0.001 to 0.006). No relationship could be identified between nerve injury and pain (p = 0.21-0.97). In week 6, the presence of pain and a nerve injury were significantly associated with lower TAM scores (p = 0.001). In week 13, pain during motion (p < 0.001) and the presence of a nerve injury (p = 0.036) were significantly associated with worse DASH scores. Patient satisfaction was significantly inversely correlated to pain during motion in weeks 13 and 26 (p < 0.001). Conclusion: We found a significant relationship between pain during motion and pain medication intake, TAM, DASH scores and patient satisfaction. It is therefore advisable to closely monitor this parameter after flexor tendon injuries. Study registration: This multi-center cohort study is registered under https://clinicaltrials.gov: NCT04312412.

Encircling tendon repair site with collagen sheet in flexor zone 2: retrospective study.

BACKGROUND: Peritendinous adhesion is the most common complication of tendon repairs in the hand and often requires surgical intervention, resulting in increased labor loss and increased treatment costs. Many agents used to reduce tendon adhesion in animal models, however these agents have not entered clinical use. This study is the first-ever clinical study that evaluates encircling tendon repair site with collagen sheet as an anti-adhesion barrier. METHODS: Between December 2014 and January 2020, 156 patients included in this study, with clean cut isolated flexor digitorum profundus (FDP) tendon injury in flexor tendon zone 2. All tendons repaired with modified double Kessler technique. In 76 patients, tendon repair site encircled with collagen sheet. 80 patients were randomly selected from our clinical records and functional results are compared with Strickland's total active motion grading system. RESULTS: The mean total range of motion was 79% in the control group and 81% in the collagen sheet group, and there was no statistically significant difference between the two groups (Z: - 1.393, p = 0.164). In the control group, very good and good repair according to Strikland classification was 65/80 (81%). In the collagen sheet group, it was 62/76 (82%), respectively. There was statistically significant difference between 5 FDP TAM measurements between collagen sheet and control group (t(35) = 0.29, p = 0.016, p < 0.05). The mean TAM of the 5 FDP tendons in the collagen sheet group: 83.8 (SD: 8.2) in the and 76.1 (SD: 9.5) in the control group. CONCLUSIONS: For the first time in the literature, functional results of Zone 2 flexor tendon repair using collagen sheets in patients with clean cut tendon injuries reported. However, there were no statistical difference about total active motion between control and collagen sheet group, 5th FDS tendon repairs encircled with collagen sheets had better outcomes. Prospective studies in patient groups with high adhesion risk are recommended.

Outcomes of 218 primary single-finger flexor tendon repairs up to 1 year after surgery: a multicentre cohort study.

In this retrospective multicentre cohort study, we present the results of primary single-finger flexor tendon repairs in zones 1 to 3 between 2014 and 2021. Data from 218 patients were retrieved with their demographics, injury and surgery characteristics and therapy outcomes. The data were systematically collected and analysed at predefined time points up to 1 year after surgery. A good to excellent return of motion was achieved by 77% (Tang classification) and 92% (American Association for Surgery of the Hand classification) of patients at 1 year. The tendon rupture rate was 8.7%. Time had a significant impact on the recovery of finger motion and grip strength of up to 1 year, of patient satisfaction and upper extremity function up to 26 weeks, and of pain up to 13 weeks after surgery. Our results demonstrate that it is worthwhile to assess therapy outcomes over various measurement periods, as some outcomes may continue to improve up to 1 year after flexor tendon repair surgery.Level of evidence: III.

Flexor Tendon Repair: Avoidance and Management of Complications.

The proper technique for flexor tendon repair has been well established through numerous bench science and clinical studies. However, less is known about strategies to avoid and manage postoperative complications. This article discusses the common complications after flexor tendon repair, such as repair site rupture and adhesion formation. This article also addresses strategies to prevent and manage these complications. The foundation for preventing many of these complications is ensuring a strong repair without gapping at time zero, which will enable the accrual of tensile strength through early initiation of motion.

Inflammatory reaction to suture materials after flexor tendon repair. A retrospective study of 594 patients.

We report granuloma formation after using FiberWire® for flexor tendon repairs. Four subcutaneous granulomas were identified in 115 patients with FiberWire® core sutures, none in 426 with braided polyester. Foreign body reactions were found in the granuloma cases. We suggest early suture removal if this specific complication is encountered.

Wide-Awake Local Anesthesia No Tourniquet (WALANT) for Flexor Tendon Repairs as Change in Practice During the COVID-19 Pandemic: A Retrospective Cohort Study With Outcomes.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic forced many changes. In our unit, there was a significant shift from traditional anesthesia (TA) which included general or regional anesthesia, to Wide-Awake Local Anesthesia No Tourniquet (WALANT) for the treatment of flexor tendon injuries. Zones I and II injuries have always been a challenge. The primary aim of this study is to compare the 12-week range of motion (ROM) flexor tendon repair outcomes between the TA group and wide-awake (WA) group patients. The secondary aim is to compare the complications and the follow-up rate between the two groups. METHODS: All patients who underwent a primary finger flexor tendon repair in zone I or II without tendon graft for closed avulsions or open lacerations between April 2020 and March 2021 were included in the study. Electronic medical records were reviewed to record demographics, follow-up, ROM outcomes and complications. RESULTS: Forty-four patients with 49 injured fingers were in the WA group, and 24 patients with 37 injured fingers were in the TA group. A complete follow-up with 12-week ROM outcomes was available for 15 patients with 16 injured fingers in the WA group and nine patients with 13 injured fingers in the TA group. Excellent to good outcomes in the WA group were reported in 56% of the cases versus 31% in the TA group, although the difference was not statistically significant. There were similar complications in both groups, with an overall rupture rate of 11.6%, a tenolysis rate of 3.5% and a reoperation rate of 9.3%. Complete 12-week follow-up was completed by 41% of patients overall after taking tendon ruptures into account. CONCLUSIONS: This is one of the first studies comparing zones I and II flexor tendon ROM outcomes between WA anesthesia and TA. Overall, there was a trend toward superior ROM outcomes in the WA group, with similar complication rates in both groups. The difference between ROM outcomes was not statistically significant and the small sample size undermined the strength of the study. To provide stronger evidence, better-designed prospective studies are suggested that would compare WA techniques with TA techniques.

Comparison of the Outcomes of Flexor Tendon Repair in Zone II Using the Original and Adjusted Strickland Scores and the 400-Points Hand Test.

Background: The purpose of this study was to report the outcomes of flexor tendon repair in zone II and compare two analytic tests - the original and adjusted Strickland scores - and a global hand function test, the 400-points test. Methods: We included 31 consecutive patients (35 fingers) with a mean age of 36 years (range 19-82 years) who underwent surgery for a flexor tendon repair in zone II. All patients were treated in the same healthcare facility by the same surgical team. All the patients were followed and evaluated by the same team of hand therapists. Results: At 3 months after the surgery, we found a good outcome in 26% of patients with the original Strickland score, 66% with the adjusted one and 62% with the 400-points test. Among the 35 fingers, 13 of them were evaluated at 6 months after the surgery. All the scores had improved with 31% good outcomes in the original Strickland score, 77% in the adjusted Strickland score and 87% in the 400-points test. The results were significantly different between the original and adjusted Strickland scores. Good agreement was found between the adjusted Strickland score and the 400-points test. Conclusions: Our results suggest that flexor tendon repair in zone II remains difficult to assess based solely on an analytic test. It should be combined with an objective global hand function test, such as the 400-points test, which appears to correlate with the adjusted Strickland score. Level of Evidence: Level IV (Therapeutic).

The effects of NF-κB suppression on the early healing response following intrasynovial tendon repair in a canine model.

The highly variable clinical outcomes noted after intrasynovial tendon repair have been associated with an early inflammatory response leading to the development of fibrovascular adhesions. Prior efforts to broadly suppress this inflammatory response have been largely unsuccessful. Recent studies have shown that selective inhibition of IkappaB kinase beta (IKK-ß), an upstream activator of nuclear factor kappa-light chain enhancer of activated B cells (NF-κB) signaling, mitigates the early inflammatory response and leads to improved tendon healing outcomes. In the current study, we test the hypothesis that oral treatment with the IKK-ß inhibitor ACHP (2-amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-piperidin-4-yl nicotinenitrile an inhibitor) will modulate the postoperative inflammatory response and improve intrasynovial flexor tendon healing. To test this hypothesis, the flexor digitorum profundus tendon of 21 canines was transected and repaired within the intrasynovial region and assessed after 3 and 14 days. Histomorphometry, gene expression analyses, immunohistochemistry, and quantitative polarized light imaging were used to examine ACHP-mediated changes. ACHP led to reduction in phosphorylated p-65, indicating that NF-κB activity was suppressed. ACHP enhanced expression of inflammation-related genes at 3 days and suppressed expression of these genes at 14 days. Histomorphometry revealed enhanced cellular proliferation and neovascularization in ACHP-treated tendons compared with time-matched controls. These findings demonstrate that ACHP effectively suppressed NF-κB signaling and modulated early inflammation, leading to increased cellular proliferation and neovascularization without stimulating the formation of fibrovascular adhesions. Together, these data suggest that ACHP treatment accelerated the inflammatory and proliferative phases of tendon healing following intrasynovial flexor tendon repair. Clinical Significance: Using a clinically relevant large-animal model, this study revealed that targeted inhibition of nuclear factor kappa-light chain enhancer of activated B cells signaling with ACHP provides a new therapeutic strategy for enhancing the repair of sutured intrasynovial tendons.