Functional outcomes of two-stage flexor tendon reconstruction in zone 2 of the hand

INTRODUCTION

The flexor tendon system, consisting of the flexor digitorum superficialis and flexor digitorum profundus, functions within a fibro-osseous sheath stabilized by annular and cruciate pulleys.^1,2 Zone II, historically described as “no man’s land,” extends from the distal palmar crease to the insertion of the FDS tendon and is particularly prone to adhesion formation following injury.^3,4

Although primary repair remains the gold standard for acute injuries, delayed presentation, failed repair, dense scarring, and pulley insufficiency often necessitate staged reconstruction.^5-7 Hunter and Salisbury first described two-stage tendon reconstruction using silicone rod implantation to create a pseudosheath, followed by tendon grafting.⁸ Paneva-Holevich later modified this method using a pedicled FDS graft to enhance vascularity and gliding characteristics.^9,10

Despite substantial literature from Europe and Asia published data from the Arabian Peninsula remain limited.^11-13 Differences in injury patterns, occupational demands, and rehabilitation compliance may influence outcomes. This case series evaluates the functional results, complications, and prognostic variables of the Paneva-Holevich technique in an Omani cohort.

CASE SERIES

This retrospective case series was conducted at Khoula Hospital, Muscat, Oman, between January 2012 and January 2020.

Patients with age ≥8 years, zone II flexor tendon injury, underwent two-stage reconstruction using Paneva-Holevich technique and minimum 6-month follow-up were included from the study.

Patients who had thumb injuries, severe crush injuries with extensive tissue loss and incomplete records were excluded from the study.

Patient characteristics

Twenty-one patients met inclusion criteria. The mean age was 21.3±9.8 years, with male predominance (85.7%). The dominant hand was affected in 61.9%. The little finger was most commonly involved (33.3%). Mean delay to first-stage surgery was 13.8 months. Preoperative prognosis according to Boyes and Stark classification was good in 66.7%, fair in 23.8%, and poor in 9.5%.¹⁹

Surgical technique

Stage one

Scar excision and adhesion release were performed through a Brunner incision. A silicone Hunter rod was inserted and secured distally to the FDP stump and proximally to the musculotendinous junction. Pulley reconstruction (A2/A4) was performed when required.

Stage two: (4-7 months later)

The rod was replaced with a tendon graft (palmaris longus, FDS slip, or extensor digitorum communis). Distal fixation utilized a modified Kessler technique; proximal fixation used Pulvertaft weave. Tension was adjusted to restore digital cascade.

Rehabilitation protocol

Weeks 0-4: Dorsal blocking splint; passive flexion, active extension, weeks 4-6: Active motion and week 6 onward: Strengthening.

All patients underwent supervised physiotherapy for 12 weeks.

Functional outcomes

Mean TAM wasc85.4%±12.3%, mean adjusted Strickland was 82.2±14.1%, Buck-Gramko ratings were Excellent: 90.5% and good: 9.5%. Mean QuickDASH: 8.5±7.2. the 95% reported satisfaction. The 85% returned to previous occupation (mean 5.2 months).

Complications

Six patients (28.6%) required reoperation: Pulley rupture (2), volar plate contracture (1), symptomatic scar (1), wrist contracture (1) and tenolysis (1)

Complication group showed significantly lower TAM and higher QuickDASH scores (p<0.01).

No demographic or graft-type variable significantly influenced outcomes.

DISCUSSION

Zone II flexor tendon injuries remain among the most technically demanding conditions in hand surgery due to the confined fibro-osseous sheath, high risk of adhesion formation, and frequent pulley compromise.^1-4 When primary repair fails or presentation is delayed, two-stage reconstruction remains the most reliable salvage option.^5-7 This case series demonstrates that the Paneva-Holevich modification provides excellent functional recovery within our population, with a mean TAM of 85.4% and mean Adjusted Strickland score of 82.2%.

Comparison with International Literature

Our results compare favorably with previously published series. Beris et al reported a mean Strickland score of 73% in 22 patients undergoing staged reconstruction using a silicone rod and pedicled intrasynovial graft.¹² Naam reported excellent or good results in 82% of cases using a pedicled FDS graft.²¹ Similarly, Darlis et al documented satisfactory outcomes in pediatric populations.²⁰

The 100% excellent/good rate in our cohort according to Buck-Gramko criteria slightly exceeds the 82-90% range reported in most international series.^20,21 While caution is warranted given sample size, this finding may reflect strict adherence to a standardized rehabilitation protocol and meticulous pulley reconstruction during stage one.

Functional and patient-reported outcomes

Modern hand surgery increasingly emphasizes patient-reported outcome measures in addition to objective range-of-motion data.^22,23 Our mean QuickDASH score of 8.5 indicates minimal residual disability and correlates with the high satisfaction rate (95%) and return-to-work rate (85%). These findings highlight that staged reconstruction can restore not only motion but meaningful functional independence. In a young, predominantly working-age population such as ours, restoration of grip function and occupational capacity is particularly critical. Average return-to-work time of 5.2 months aligns with reported timelines in comparable series.^24,25

Complications and secondary procedures

Overall complication rate of 28.6% falls within expected range of 15-35% for staged flexor tendon reconstruction.^24,25 Pulley rupture and adhesion formation remain the most frequent causes of reoperation in literature.²⁶ Importantly, in our series, all complications were surgically addressed with acceptable secondary outcomes.

The significantly lower TAM and higher QuickDASH scores in complication subgroup confirm that secondary procedures meaningfully affect short-term functional recovery. However, even in these patients, eventual functional improvement was achievable, underscoring importance of close postoperative monitoring.

Prognostic factors

Unlike Djerbi et al who identified injury severity and smoking as negative predictors, we found no statistically significant association between demographic variables, graft type, or dominance and final outcome.²⁷ This may suggest that surgical technique and structured rehabilitation exert a stronger influence than baseline demographic factors. However, the relatively small cohort limits the statistical power to detect subtle associations.

Technical considerations

The Paneva-Holevich technique offers theoretical advantages over free tendon grafting, including improved vascularity and smoother gliding due to intrasynovial characteristics of the pedicled FDS graft.^9-12 Careful tension adjustment during stage two remains critical to avoid flexion contracture or lag.

Additionally, consistent pulley reconstruction at stage one likely contributed to the favorable outcomes observed. Preservation or reconstruction of A2 and A4 pulleys remains essential to prevent bowstringing and optimize biomechanical efficiency.^1,3

Strengths

Use of multiple validated functional scoring systems, inclusion of patient-reported outcome measures, standardized surgical technique by experienced hand surgeons, structured rehabilitation protocol and regional data from an underreported geographic area

Limitations

Limitations were retrospective design, single-center experience, small sample size, mean follow-up of 9 months may not capture long-term degenerative changes and lack of baseline preoperative PROMs.

Despite these limitations, this series contributes valuable regional evidence supporting staged reconstruction in delayed zone II injuries.

CONCLUSION

Two-stage flexor tendon reconstruction using the Paneva-Holevich technique remains a reliable and reproducible strategy for complex zone II injuries. In this case series, excellent objective and patient-reported outcomes were achieved with acceptable complication rates. The technique continues to be a valuable option in settings where delayed presentation and failed primary repair are common.

Recommendations

Future research should focus on prospective multicenter studies with larger sample sizes and longer follow-up durations to better define prognostic factors. Incorporation of baseline patient-reported outcome measures would strengthen longitudinal assessment. Exploration of wide-awake local anesthesia techniques may further optimize intraoperative graft tensioning and potentially improve outcomes. Development of standardized regional rehabilitation protocols may enhance consistency of postoperative recovery.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

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