Early or delay? The most suitable rehabilitation protocol for “no man's land” injury: Meta-analysis with trial sequential analysis

Abstract

Objective: The aim of this study is to analyze various rehabilitation protocol and determine which methods will yield a better outcome. Methods: The database reports were searched within 1990 until 2020, using PubMed, Cochrane library database, Ovid, Medline, and the other several published trials. A statistical analysis was made from Review Manager and Trial Sequential Analysis (TSA). Result: The mean of rerupture rate is 3.3% (n = 8) in the combination protocol and 8% (n = 48) in controlled active motion (CAM) protocol. Meta-analysis found no significant difference between Kleinert versus CAM in rerupture rate. Furhtermore, we found no significant difference in Duran versus CAM in rerupture rate. In TSA, the Z-curve does not cross both of the trial sequential boundaries, a further trial with larger sample will be required. The TSA of flexion contracture CAM versus Kleinert was indicated that CAM protocol may be superior than Kleinert to reduce the incidence of flexion contracture with the range of mean flexion contracture 6.6% (n = 18) in CAM to 23.6% (n = 76) in Kleinert protocol. Conclusion: Current meta-analysis proposed that the combination technique will result less rerupture incidence and better functional outcome in flexor zone II injuries than other techniques. The CAM method also results in less flexion contracture than others. However, a further meta-analysis with larger sample trials seems to be required to confirm this review's conclusion.

Keywords

Tendon injuries postoperative care surgical procedures operative

Introduction

Previously, prior to 1970s, the preliminary studies considered the rehabilitation methods on flexor tendon injury postsurgical repair focused on keeping the flexor tendon immobilized for the first 3 weeks.¹ However, as shown in the previous studies, the tendon's tensile strength will be low at this stage. The purpose of this rehabilitation methods after surgical repair is to yield normal function and tendon gliding movement, yet, to avoid the tendon rerupture, flexion contracture and scar adherence.^2,3 Flexor tendon injury can be a challenging process for most hand surgeon due to several clinical problems, for example; flexor tendon injury should be managed with operative treatments. Flexor tendon will not heal spontaneously without surgery because the end of tendon should bring together to promote healing. On the other hand, postsurgical problem may result in rerupture and stiffness and postsurgical rehabilitation should be meticulously planned.^4–6 The rehabilitation postsurgery has a function to prevent tendon adhesion and improve the gliding movement, even tough, if the rehabilitation managed too aggressively, the postrepair tendon has tendency to rupture or become stiff.^7–9 Addressing injury in zone II flexor tendon may also become problematic, it needs to sustain the anatomic connection between flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendon. FDS tendon has two slips that it has to roll around the FDP tendon, to permit FDP pass through FDS and lie down in the superficial champers chiasma. When the hand surgeon fails to remake this anatomical relationship, it will restrain tendon to glide and increase the risk of adhesion and restrict the digital movement.^10,11

In the middle of 1970s, Duran and Houser,¹² delineate their method which involved “controlled passive motion” and reported that the restrictive adhesions tendon may be prevented with 3 until 5 mm length of tendon excursions. Concomitantly, Kleinert et al.¹³ investigated the promising outcome using direct passive motion postsurgical with a rubber band as an orthosis to pull back the finger and permit active finger extension, with producing passive flexion movement of finger. His study revealed that the mobilized tendon postoperative showed less adhesion and faster healing rate than prolonged immobilized tendon.

The progression of modification rehabilitation protocols following flexor tendon injury grows rapidly since then, accompanying with furtherance in surgical methods and materials. On the other hand, there is still a debatable area to determine the ideal rehabilitation methods to achieve a functional outcome of post-tendon repair, although, many previous publishing reports have declared a novel rehabilitation protocol.^14,15

There are many varieties of rehabilitation methods regarding flexor tendon injury, yet the principal methods are “active extension-passive flexion” by Kleinert et al.¹³ using rubber band orthosis. In the second place, “controlled passive movement” (Duran and Houser protocol) used a passive motion within range 3 to 5 mm of the involved digits followed by active digit flexion. The last protocol is the combination between Kleinert and Duran protocol. Chesney et al.¹⁶ in their study has compared those three protocols’ overview following postsurgical repair in zone II flexor tendon injury and generated that the combined technique resulted less incidence of tendon rerupture and more tolerable range of motions.¹⁷

Formerly, there has been several published systematic review and meta-analysis which has been compared, one of them is published by Thien et al.¹⁸ in Cochrane library. However, this study has only included the randomized controlled trial (RCT) report. There were three full-text reports of RCT and the other three were just abstract. It concluded that the best regimen method may not be defined due to insufficient verification of trial studies.

Our review comprehensively included RCT and observational reports of the past 20 years published data, we specified our search filtered on to rehabilitation methods in flexor zone II injury “no man's land.” This review is deliberately pursuing the answer of “which rehabilitation protocols in ‘no man's land’ injury can generate the best functional outcome post-surgical repair.”

Materials and methods

Search strategy

The author seeks the relevant articles according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We used this guideline as a set of evidence-based items to improve our systematic reviews and meta-analysis. At first, the database reports were collected through fastidious search within range 1990 until 2020, using PubMed, Cochrane library database, Ovid, Medline, and the other several published trial registries. We included all the studies with evidence based ranging from levels I to IV. The criteria of this review's study emphasized on clinical assessment, with the subject matter of the tendon rupture prevalence, flexion contracture, and functional outcome scoring using Strickland Criteria, The Buck-Gramcko Classification and Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire following the early phase rehabilitation protocol (3 weeks) postsurgical repair in zone II flexor injury, categorized as a passive motion (Kleinert and Duran type protocol), controlled active motions (CAMs), and combination of those protocols. We analyzed each study for odds ratio (OR) for dichotomous models with 95% confidence interval (CI) and further measured using Review Manager (RevMan) (Computer program, Version 5.3. Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2014). The result's heterogenicity was elaborated as a fixed effect model if heterogeneity was <50% and the random effect model if heterogeneity was >50%.

Our initial search keywords are using “rehabilitation” and “flexor tendon” resulted in 263 articles. Furthermore, we add more keywords following the Boolean operators: Kleinert protocol OR controlled active motion OR modified kleinert rehabilitation AND duran protocol OR duran houser rehabilitation OR early passive mobilization OR early passive motion OR combination active-passive motion AND flexor tendon injury zone 2 OR hand flexor tendon rupture zone 2. Sixteen articles were included, and the total sample is 1.321 populations (Figure 1).

Figure 1.

Article selection scheme.

All of the literature's component including the report's eligibility, qualification, critical appraisal, the selection studies, and trial object, also bias risk assessment, were judged by independent authors. Critical appraisal of literature is using Critical Appraisal Skill Program (CASP) question checklist on each included study.¹⁹

Statistical analysis

The author also measured mean difference for continuous outcome and OR for dichotomous outcome, using 95% CI. It was enumerated using RevMan (Computer program, Version 5.3. Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2014). A heterogenicity interstudy was assessed by χ² test, each study heterogenicity will be assumed if I² > 50% and p value <0.1. The result data will be categorized as a significant if p value <0.05. To create the threshold in our meta-analysis, yet, to determine the reliable significance-based result and this review's impact of the information amount due to small sample size and low study's quality, we used trial sequential analysis by the statistical software, Trial Sequential Analysis (TSA) version 0.9 beta (User Manual for TSA, Copenhagen Trial Unit 2011). The reports will be considered to have sufficient level evidence if the Z-curve cross the upper and lower boundaries or futility line. However, if the Z-curve does not cross the boundaries, the required information size had not been reached and there will be insufficient evidence to have the conclusion.

Methods

The specification criteria for this review

Types of studies

The author incorporated all type studies; included case series, cohort studies, quasi-randomized and nonrandomized study, RCT with range of evidence level varies from levels I to IV (Table 1).

Table 1.

Validity search methods.

Authors	Journal	Randomized Study	Study Design	Level of Evidence
May, 1991	Journal of Hand Surgery	No	Prospective Case Series	IV
Bainbridge, 1994	Journal of Hand Surgery	No	Prospective Comparative Study	II
Elliot, 1994	Journal of Hand Surgery	No	Prospective Comparative Study	II
Silverskiold, 1994	Journal of Hand Surgery	No	Prospective Case Series	IV
Baktir, 1996	Journal of Hand Surgery	No	Prospective Comparative Study	II
Schenk, 1996	Journal of Hand Surgery	No	Prospective Case Series	IV
Peck, 1998	Journal of Hand Surgery	Yes	Prospective Comparative Study	II
Cetin, 2001	American Journal of Physical Medicine & Rehabilitation	No	Prospective Case Series	IV
Galanakis, 2003	Journal of Acta Orthopaedica Belgica	No	Case series	IV
Silva, 2005	Journal of Hand Surgery, france	No	Prospective Comparative Study	II
Osada, 2006	Journal of Hand Surgery	No	Case series	IV
Yen, 2008	Journal of Hand Surgery	No	Prospective Comparative Cohort	II
Kitis, 2008	Journal of Plastic Reconstruction Hans Surgery	No	Prospective Comparative Study	II
Trumble, 2010	The Journal of Bone and Joint Surgery	Yes	Randomized Controlled Trial Study	I
Frueh, 2014	Journal of Hand Surgery	No	Retrospective Comparative Study	III
Sabour, 2018	Journal of Egyptian Rheumatology & Rehabilitation	Yes	Prospective Comparative Study	II

Type of populations

The author particularizes the literature on human study related to early stage rehabilitation postsurgical repair in zone II flexor tendon injury.

Type of interventions

The variation of surgical method regarding zone II flexor tendon injury is well accepted on included studies followed by early stage rehabilitation:

Active extension-passive flexion (Kleinert method)

Controlled passive movement (Duran Houser protocol)

Controlled active movement

Combination technique (Kleinert, Duran Houser and controlled active movement)

The time duration regarding injury to surgical repair and rehabilitation duration may vary on each literature.

Type of result assessment:

Post-treatment complication

- Rerupture incidence

- Flexion contracture

Functional outcome assessment

- Strickland criteria

- The Buck-Gramcko classification

- DASH questionnaire.²⁰

Study quality assessments

All of the published studies were assessed and analyzed for its title and abstract as it were matched with this study's specifications. Furthermore, all of the filtered studies will be extracted to the inclusion basis. We did the critical appraisal study using checklist of CASP, then it will be finalized with the high qualification and study eligibility reviewed. All of the literature's section, comprising a study's methodological, the data variables, and risk of bias has been reviewed by the author.

Results

Study descriptions

Our electronic database summed several inclusion studies with total 16 literatures and 1.321 participants, it was divided into 4 meta-analysis and descriptive. Studies level varies from level IV evidence in 6 case series, 8 prospective cohort studies (level II evidence), 1 retrospective comparative study (level III evidence), and 1 RCT study (level I evidence) (Table 1). None of the included studies were compared altogether of those included protocols. There were 6 studies which outlined only one specific rehabilitation protocol and 10 other studies compared between Kleinert, Duran, CAM, and the combined rehabilitation protocol.

Surgical technique

Most of the studies (10 reports) used a tendon repair technique which involved two-strands suture across the tendon. Two studies used a four-strand suture and one study used six-strand core suture. Two studies did not explain the repair tendon technique. In this review, we did not identify the correlation between suture strands number and the rerupture rate (Table 2).

Table 2.

Study's characteristic.

Study, year publication	Sample sizeNumber digits	Flexor Zones	Method of Rehabilitation	Splint TypeTotal Follow Up	Suture Repair Method	Functional Outcome (P Value)	Complication
May, 1991 (9)	140 patients 159 digits	Zone II	Gr 1: Modified kleinert: 54 digits Gr 2: Modified kleinert + passive control: 51 digits Gr 3: Dynamic flexion traction + nighttime extension: 54 digits	Gr 1: dorsal plaster splint w/ wrist in 30° - 45° flexion, MCP in 50° - 70° flexion and IP extension. Gr 2: dorsal plaster splint w/ wrist in 30° - 45° flexion, MCP in 50° - 70° flexion, and IP full extension. Group 3: dorsal plaster splint extend to PIP, w/ wrist 30° - 45° flexion, MCP 50° - 70° Flexion, IP extension. Foll-up at 6 mo and 1 y	FDP: modified Kessler 4-0 w/ braided polyester 6-0 epitendinous stitch FDS: mattress sutures 4-0 braided polyester 2-strand repair	Strickland: Gr 1: 72% good-excellent Gr 2: 62% good-excellent Gr 3: 83% good-excellent	Gr1: 2 ruptures 15 extension deficit Gr 2: 1 rupture 14 extension deficit Gr 3: 2 ruptures 3 extension deficit
Bainbridge, 1994 (10)	Group 1: 52 patients, 68 digits Group 2: 56 patients, 67 digits	Zone I,II	Group 1: passive flexion – active extension Group 2: controlled active motion	Group 1: dorsal splint w/ wrist 30° flexion, MCP 90° flexion, and IP neutral Gr 2: dorsal splint W/ wrist 30° flexion, MCP 90° flexion, and IP full extension Foll-up: 4 mo	FDP: modified Kessler of 3-0 / 4-0 Prolene w/ epitendinous 6-0 nylon / Prolene FDS: 4-0 or 5-0 horizontal mattress sutures 2-strand repair	Buck-Gramcko: Gr 1: zone I: 90% good-excellent zone II: 50% good–excellent Gr 2: zone I: 89% good–excellent zone II: 90% good–excellent Strickland: Gr 1: zone I: 10(90%) good –excellent zone II: 31(53%) good-excellent Gr 2: zone I: 16(89%) good–excellent zone II: 46(94%) good–excellent ASSH: Gr 1: zone I: 7(70%) good –excellent zone II: 27(46%) good-excellent Gr 2: zone I: 16(89%) good–excellent zone II: 47(92%) good–excellent Zone 1: P>0.05 Zone 2: P<0.001	Gr 1: 2 ruptures 27 extensor deficits Gr 2: 5 ruptures 7 extensor
Elliot, 1994 (11)	233 patients 137 tendons	Zone I,II	Controlled active motion	Thermoplastic dorsal splint w/ 30° wrist flexion, 30° MCP flexion, and IP neutral Foll-up: 3 mo	FDP: 3-0 / 4-0 Prolene and 6-0 Prolene / nylon epitendinous FDS: horizontal mattress of 4-0 / 5-0 nylon 2-strand repair	Strickland: 77% good–excellent	18 ruptures
Silverskiold, 1994 (12)	46 patients 55 digits	Zone II	Active extension and passive/ active flexion	Dorsal splint PIP, w/ wrist at 0°, MCP in 50° - 70° flexion, and IP fully extend foll-up: 6 wks and 6 mo	FDP: modified Kessler—4-0 polyester and 6-0 polypropylene epitendinous 2-strand repair	DIP and PIP had 82% and 88% ROM Strickland: Excellent-good: 53%	2 ruptures
Baktir, 1996 (13)	77 patients 88 digits	Zone II	Gr 1: 33 digits: Kleinert-rubber band passive flexion/active extension method Gr 2: 38 digits: early active mobilization	Gr 1: dorsal splint W/ wrist 30° - 40° flexion, MCP in 70°- 90° flexion, and IP full extension Gr 2: dorsal splint w/ wrist 0° flexion, MCP 70°- 90° flexion, and IP full extension Foll-up: 1 yr	FDP: modified Kessler—4-0 braided polyester and epitendinous 6-0 Prolene FDS: horizontal mattress sutures— 4-0 braided polyester 2-strand repair	Strickland: Gr 1: 78% good–excellent and 84% mean grip strength Gr 2: 85% good–excellent 90% mean grip strength	Gr 1: 2 re-ruptures Gr 2: 2 re-ruptures Flexion contracture: 10 in Gr 1 5 in Gr 2
Schenk, 1996 (14)	33 patients 44 digits	Zone II	The Washington regimen: passive flexion& extension, followed active extension& passive flexion, active extension & active flexion	Dorsal splint thermoplastic Foll-up: 3 and 6 mo	Gr 1: kleinert et al modification of bunnel suture tech, 4.0 nylon- 31 finger Gr 2: modified Kessler grasping suture, 6.0 nylon – 13 finger	Strickland and glogovac: Excellent After 3 mo – 3 patients After 6 mo – 4 patients 36% total excellent	No complication
Peck, 1998 (15)	52 patients 52 digits 92 tendons	Zone II	Gr 1: controlled active motion - 26 digits Gr 2: modified Kleinert: 26 digits	Gr 1: thermoplastic dorsal splint wrist 40° flexion MCP 60° flexion, IP neutral Gr 2: thermoplastic dorsal splint wrist 40°flexion, MCP 60° flexion, IP neutral Foll-up: 12 wks	FDP: modified Kessler 3-0 Prolene,6-0 nylon / Prolene epitendinous FDS: horizontal mattress 6-0 prolene. 2-strand repair	Strickland: Gr 1: 85% good - excellent Gr 2: 69% good- excellent P >0.05	Gr 1: 12 re-ruptures Gr 2: 2 re-ruptures
Cetin, 2001 (16)	37 patients 74 digits	Zone I-V	Controlled mobilization foll. w/ combined (modified Kleinert and modified Duran) Kleinert splint with a palmar pulley	Dorsal splint wrist 30° - 35° flexion and MCP flexion 50° - 60° Foll-up: 12.9 wks	Modified Kessler 4-0 Prolene with 6-0 nylon epitendinous 2-strand repair	Buck-Gramcko: 97% good–excellent	1 rupture 13 extensor deficits
Galanakis, 2003 (17)	19 patients 23 digits	Zone II	Passive flexion-active extension	Dorsal splint, full extension PIP, DIP, 30⁰ palmar flexion, 70-90⁰ MCP flexion Foll-up: 20 wks	Modified Kessler 4.0 nylon repair core suture 2 strand repair	Strickland: 15 sample: excellent 5 sample: good 2 sample: fair	2 ruptures
Silva, 2005 (18)	82 patients 136 digits	Zone II	Early active mobilization	N/A Foll-up: 12-36 wks	Modified Kessler 3-0 nylon with 5-0 epitendinous 2-strand repair	IFSSH and Strickland criteria: Long fingers: 98% good – excellent (Strickland); 82% good (IFSSH) Thumb: 96% good–excellent (Strickland); 96% good– excellent (IFSSH)	5 ruptures
Osada, 2006 (19)	21 patients 27 digits	Zone II	Controlled active mobilization (active extension and passive/active flexion)	Dorsal splint, wrist neutral, MCP joint 30-40⁰ flexion, IP joint full extended Foll-up range 13 mo	Gr 1: Y1 tech.-6 strands repair- 11 digits Gr 2: Tsuge suture + looped thread with modified Kessler 2-strand repair-8 digits	Strickland criteria: Gr 1: Excellent – 11 digits Good –7 digits Fair – 1 digits Gr 2: Excellent – 6 digits Good –2 digits P > 0.05 ROM: avg flex 62⁰ DIP, 91⁰ PIP	0 ruptures
Yen, 2008 (20)	20 patients	Zone II	Active extension, active place an hold- 10 digits Kleinert method- 10 digits	Dorsal splint with wrist in 30° flexion, MCPs in 70° flexion, and IPs in full extension Foll-up: 4 mo	4-0 Prolene core sutures plus 6-0 Prolene circumferential sutures 4-strand repair	Mayo Wrist Score: Active motion: 70% good–excellent Kleinert splint: 0% good–excellent	Active place and hold: 0 complications Kleinert splint: 1 rupture
Kitis, 2009 (21)	192 patients 263 digits	Zone II	Gr 1: modified Kleinert (Washington regimen)— 137 digits) Gr 2: controlled passive movement—126 digits	Group 1: 6 wks in Kleinert splint with wrist minus 20° full flexion, MCPs 10° to 20°flexion, IP neutral Group 2: 5 wk in dorsal splint wrist 20° flexion, MCP 50° flexion, IP full extension Foll-up range, 6–20 mo	Modified Kessler 4-0 nylon w/ 6-0 nylon epitendinous 2-strand repair	Buck-Gramcko excellent: Gr 1: 87% Gr 2: 75% P 0.01 Grip strength Gr 1: 89% Gr 2: 81% P 0.08 DASH Gr 1: mean 29.6 Gr 2: mean 41.7 P 0.01	Gr 1: 16 extension deficits 0 ruptures Gr 2: 26 extension deficits 1 rupture
Trumble, 2010 (22)	103 patients 119 digits	Zone II	Gr 1: Passive motion—51 patients with 58 digits Gr 2: Active motion with place and- hold—52 patients with 61 digits	N/A Foll-up: 6, 12, 36, 52 wks	FDP: Strickland Method, 2 core sutures 3-0 polyester and 6-0 Prolene epitendinous FDS: simple Kessler with 3-0 polyester 4-strand repair	ROM: Gr 1-52 wks: 128⁰± 22⁰ Gr 2- 52 wks: 156⁰± 25⁰ P<0.05 DASH: Gr 1: 3.1 ± 4.3 Gr 2: 2.0 ± 3.7 P<0.05 Satisfaction score: Gr 1: 8.2 ± 3.9 Gr 2: 9.4 ± 4.3	Gr 1: Passive motion: 2 ruptures Gr 2: Active motion: 2 ruptures Flexion contracture: Gr 1: 28⁰±13⁰ Gr 2: 15⁰± 8⁰ P < 0.05
Frueh, 2014 (23)	132 patients 159 digits	Zone I, II	Gr 1: Early passive mobilization (EPM)- 138 Gr 2: Controlled active motion (CAM) – 21 Other combination protocol - 72	Gr 1: EPM with Dorsal 4 finger orthosis (wrist 30°flexion, intrinsic plus position of finger) foll. Rubber band for passive finger flexion Gr 2: CAMdorsal forearm orthosis Foll-up: 4 and 12 wks	FDP & FDS 4 strands core suture with locking loops	Total active motion Wk 4-CAM : EPM = P<0.001 Wk 12-CAM : EPM P = 0.75 Functional grades (AASH) in 12 wks: EPM: excellent 8 pt (53%) CAM: good 65 pt (63%) P > 0.05	Rupture rate: EPM: 10 rupture (7%) CAM: 1 rupture (5%) P > 0.05 Other protocol: 8% rupture
Sabour, 2018 (24)	26 patients 36 tendons	Zone I,II,III	Gr 1: early passive rehabilitation (modified kleinert – passive flexion and active extension)- 20 pt Gr 2: early active rehabilitation (place and hold)- 16	Dorsal blocking splint wrist 20⁰ flexion, MCP 70⁰ flexion IP joint full extension Foll-up: 12 wks	Modified Kessler technique with 3.0	Patient satisfaction (analog scale): Gr 1: median: 4 (range 2-7) Gr 2: median: 6 (range 4-8.5) DASH score Gr 1: median: 15 (range 10-15) Gr 2: median: 23 (range 2-26) P=0.62	Flexion deformity DIP Gr 1: 10 tendon (50%) Gr 2: 1 tendon (6.2%) P=0.004 Flexion deformity PIP Gr 1: 8 tendon (40%) Gr 2: 3 tendon (18.7%) P=0.1 Flexion deformity DIP-PIP P=0.02 Rupture rate Gr 1: 2 (10%) Gr 2: 1 (6.25%) P>0.05

Primary outcome: Rerupture rate

We summarized the average rate of rerupture per rehabilitation protocol with the highest mean of rerupture rate is the CAM protocol at 8% (n = 48, N = 593). The mean range of rerupture is 3.3% to 8% across all of the studies. The lowest of mean rate followed by the combination protocol (Kleinert and Duran type) at 3.3% (n = 8, N = 241) (Table 2). From the meta-analysis calculation between the comparison of Kleinert rehabilitation protocol versus CAM which used fixed effect model for dichotomous outcome, it was found that there was no significant difference in terms of rerupture rate between those two rehabilitation models (heterogeneity, I² = 40%; OR = 1.64 95% CI, 0.55 to 4.92; p = 0.37). It was also found that there was no statistically difference between Duran and CAM protocol in rerupture rate (heterogeneity, I² = 0%; OR = 1.37 95% CI, 0.40 to 4.74; p = 0.62). In trial sequential analysis, the Z-curve does not cross both of the trial sequential boundaries, the calculation of required information size was 169, yet, a further trial with larger sample will be required (Figure 2).

Figure 2.

Comparison: Kleinert rehabilitation protocol versus CAM; outcome: rerupture (digits); Duran rehabilitation protocol versus CAM; outcome: rerupture (digits); Kleinert rehabilitation protocol versus CAM; outcome: flexion contracture (digits); Kleinert rehabilitation protocol versus CAM; outcome: Strickland criteria (excellent–good). CAM: controlled active motion; CI: confidence interval.

Primary outcome: Flexion contracture

The range mean of flexion contracture is 6.6% to 23.6%, with the highest mean of flexion contracture rate is Kleinert protocol at 23.6% (n = 76, N = 322) and the lowest mean rate is CAM at 6.6% (n = 18, N = 273). The meta-analysis between Kleinert and CAM used random effect model for dichotomous outcome and was found statistically significant in flexion contracture rate (heterogeneity, I² = 0%; OR = 4.48 95% CI, 2.48 to 8.07; p < 0.00001) (Figure 2). For trial sequential analysis in term of flexion contracture between CAM and Kleinert was illustrated that the Z-score crossed the upper boundary line indicated that CAM protocol may be superior than Kleinert to reduce the incidence rate of flexion contracture (Figure 2).

Secondary outcome: Functional outcome

The functional outcome for this review was divided into three outcomes. First, we identified the comparative between Kleinert, modified Kleinert type, Duran type, combination protocol (Kleinert, Duran, and CAM), and CAM based on the Original Strickland Criteria. Eleven studies had used the Strickland criteria. For meta-analyses between Kleinert rehabilitation protocol and CAM used random effect model for dichotomous outcome, found no significant difference in Strickland score (heterogeneity, I² = 79%; OR = 0.49 95% CI, 0.14 to 1.71; p = 0.26) (Figure 2).

For Strickland criteria's sum average on each study was found the highest excellent–good score (%) at the combination technique with mean 80% (n = 167), the lowest mean excellent–good score (%) is 53% (n = 138) in Duran type. The average of Strickland criteria in all protocols is 53% to 80%. Three studies had been used the Buck-Gramcko criteria. The highest excellent–good score in Buck-Gramcko criteria was found 97% (n = 74) in combination type protocol. The lowest mean is Kleinert-modified Kleinert type at 69% (n = 205). The mean of Buck-Gramcko outcome is 69% to 97%. The third outcome is DASH questionnaire, only three studies analyzed the DASH outcome which only compared Kleinert-modified Kleinert, Duran type, and CAM protocol. The highest mean score is 53.8 (n = 184) at Duran type, the lowest mean value is CAM at 36.7 (n = 77). The mean of DASH questionnaire is 36.7 to 53.8.

Discussion

Kleinert et al.¹³ introduced the first protocol method with passive flexion and active extension. Since then, there were plentiful published experimental studies about rehabilitation novel protocol. There are many hypotheses regarding to this rehabilitation protocol in flexor zone II injury appear to be questionable.²¹ One of the hardest challenges to assess this rehabilitation program is not only due to the technique of rehabilitation itself, yet it also depends on the variation of surgical technique and the functional outcome of the patient. In this review, we reveal most studies (10 reports) were using two-strand suture technique compared to the four and six strands.²²

Hung et al.² analyzed that he has used early active mobilization on zone II and other zone flexor tendon injury and achieved good–excellent result in 71% zone II repairs and 77% zone with statistically significant result. Riaz et al.³ who has also evaluated using Kleinert methods on his prospective comparative study and found that 75% digits were graded excellent using american society for surgery of the hand scoring. According to Thien et al.¹⁸ on his meta-analyses using 6 RCT, there were no significant difference between the comparison on early active motion, continuous passive motion (CPM), Kleinert and Duran protocol. He also stated that early mobilization protocol is well accepted in flexor tendon injury, yet the best regiment has not been concluded. On the other hand, Khan et al.²³ used Kleinert method on his prospective study, he analyzed 50 populations with statistically significant result that 94% patients had excellent result. Trumble et al.²⁴ reported his analysis through active motion protocol compared to passive motion. They reported the flexion contracture and range of motion were better achieved than passive protocol. On the other terms, patients with more improved joint movement stated a higher satisfaction than immobilized joint postsurgical. However, article by Peck et al.²⁵ compared the active motion protocol and modified Kleinert, 46% tendon ruptures were achieved by active motion protocol.¹³

This meta-analysis has been made to overcome the complication rate postsurgical flexor tendon injury zone II. Thus, we met some challenge of the long interval on report's trends, the repair technique may vary on each study and multitude report's variable including sample populations, the tendon injury pattern and length of rehabilitation protocol. As we know, none of the recent study did the comparative study which used all of the rehabilitation method protocols. Nevertheless, through this review and meta-analysis, our expectation is to answer the question of “what type of rehabilitation is the most suitable for no man's land injury.” We analyzed that the combination protocol which combined active and passive technique is the best protocol. Through our review, the lowest rate of rerupture incidence was achieved by the combination technique, yet, the flexion contracture is minimal on the digits which were treated by CAM.

Footnotes

Acknowledgments

We would like to thank all the people who helped us with this study.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Celleen Rei Setiawan

References

Braga-Silva

Kuyven

. Early active mobilization after flexor tendon repairs in zone two. Chir Main 2005; 24: 165–168.

Hung

Pang

Yeung

, et al. Active mobilisation after flexor tendon repair: comparison of results following injuries in zone 2 and other zones. J Orthop Surg (Hong Kong) 2005; 13: 158–163.

Riaz

Hill

Khan

, et al. Long term outcome of early active mobilization following flexor tendon repair in zone 2. J Hand Surg Br 1999; 24: 157–160.

Baktir

Türk

Kabak

, et al. Flexor tendon repair in zone 2 followed by early active mobilization. J Hand Surg Br 1996; 21: 624–628.

Bainbridge

Robertson

Gillies

, et al. A comparison of post-operative mobilization of flexor tendon repairs with “passive flexion-active extension” and “controlled active motion” techniques. J Hand Surg Br 1994; 19: 517–521.

Cetin

Dinçer

Keçik

, et al. Rehabilitation of flexor tendon injuries by use of a combined regimen of modified Kleinert and modified Duran techniques. Am J Phys Med Rehabil 2001; 80: 721–728.

Silfverskiöld

May

. Flexor tendon repair in zone II with a new suture technique and an early mobilization program combining passive and active flexion. J Hand Surg Am 1994; 19: 53–60.

Schenck

Lenhart

. Results of zone II flexor tendon lacerations in civilians treated by the Washington regimen. J Hand Surg Am 1996; 21: 984–987.

Abdel Sabour

Labib

Sallam

, et al.

Comparative study between early active and passive rehabilitation protocols following two-strand flexor tendon repair: can two-strand flexor tendon repair withstands early active rehabilitation?

Egypt Rheumatol Rehabil 2018; 45: 125–132.

10.

Griffin

Hindocha

Jordan

, et al. An overview of the management of flexor tendon injuries. Open Orthop J 2012; 6: 28–35.

11.

Kannan

Dhanaraju

. Prognostic indicators affection functional outcome in zone II flexor tendon repairs. Int Surg J 2018; 5: 3613–3616.

12.

Duran

Houser

. Controlled passive motion following flexor tendon repair in zones 2 and 3. In: AAOS symposium on tendon surgery in the hand. St Louis: Mosby, 1975, pp.105–114.

13.

Kleinert

Kutz

Atasoy

, et al. Primary repair of flexor tendons. Orthop Clin North Am 1973; 4: 865–876.

14.

Elliot

Moiemen

Flemming

, et al. The rupture rate of acute flexor tendon repairs mobilized by the controlled active motion regimen. J Hand Surg Br 1994; 19: 607–612.

15.

Frueh

Kunz

Gravestock

, et al. Primary flexor tendon repair in zones 1 and 2: early passive mobilization versus controlled active motion. J Hand Surg Am 2014; 39: 1344–1350.

16.

Chesney

Chauhan

Kattan

, et al. Systematic review of flexor tendon rehabilitation protocols in zone II of the hand. Plast Reconstr Surg 2011; 127: 1583–1592.

17.

Galanakis

Aligizakis

Katonis

, et al. Functional evaluation after primary flexor tendon repair in zone II. Acta Orthop Belg 2003; 69: 252–256.

18.

Thien

Becker

Theis

J-C

. Withdrawn: Rehabilitation after surgery for flexor tendon injuries in the hand. Cochrane Database Syst Re 2010: (10): CD003979. doi:10.1002/14651858.CD003979.pub3

19.

Singh

. Critical appraisal skills programme. J Pharmacol Pharmacother 2013; 4: 76–77.

20.

Beaton

Davis

Hudak

, et al.

The DASH (disabilities of the arm, shoulder and hand) outcome measure: what do we know about it now?

Br J Hand Ther 2001; 6: 109–118.

21.

Yen

Chan

Wong

, et al. Clinical results of early active mobilisation after flexor tendon repair. Hand Surg 2008; 13: 45–50.

22.

Osada

Fujita

Tamai

, et al. Flexor tendon repair in zone II with 6-strand techniques and early active mobilization. J Hand Surg Am 2006; 31: 987–992.

23.

Khan

Khurram

Khan

, et al. Zone 2 flexor tendon injuries: our experience with early active movement protocol for rehabilitation of tendons. Ann Med Res 2019; 26: 2110–2113.

24.

Trumble

Vedder

Seiler

III

, et al. Zone-II flexor tendon repair: a randomized prospective trial of active place-and-hold therapy compared with passive motion therapy. J Bone Joint Surg Am 2010; 92: 1381–1389.

25.

Peck

Bücher

Watson

, et al. A comparative study of two methods of controlled mobilization of flexor tendon repairs in zone 2. J Hand Surg Br 1998; 23: 41–45.

Early or delay? The most suitable rehabilitation protocol for “no man's land” injury: Meta-analysis with trial sequential analysis—20 years trends

Abstract

Keywords

Introduction

Materials and methods

Search strategy

Statistical analysis

Methods

The specification criteria for this review

Types of studies

Type of populations

Type of interventions

Type of result assessment:

Study quality assessments

Results

Study descriptions

Surgical technique

Primary outcome: Rerupture rate

Primary outcome: Flexion contracture

Secondary outcome: Functional outcome

Discussion

Footnotes

Acknowledgments

Declaration of conflicting interests

Funding

ORCID iD

References