Is the Complication Rate in the Surgical Repair of the Distal Biceps Tendon Rupture Influenced by the Timing, Type of Incision and Method of Fixation?

Abstract

Background

Distal biceps tears are uncommon injuries, typically leading to significant loss of elbow flexion and supination strength; surgical repairs restore muscular strength and endurance. The aim of this study was to compare the complication rate of early (< 21 days) vs delayed (> 21 days) repair and the effect of types of incision and fixation methods used in the repair.

Methods

A total of 86 cases were retrospectively reviewed, and 66 cases were included in the study after exclusion. Different preoperative and intraoperative variables and postoperative outcome measures were recorded. We analysed the effects of early and delayed repair, types of incision and fixation methods on the complications.

Results

31 had an early, and 35 had delayed distal biceps repair. The mean follow-up was 14.92 weeks. 13.6% had major, and 40.9% had minor complications. No significant difference was noted in complications between the two groups (54.8% vs 54.3%). Higher complications were observed when surgery was done using a single anterior incision compared to 2 anterior incisions (68.8% vs 16.7%, p=0.0002). Overall, higher (76.3% vs 25.9%, p=0.0001) complications were noted in patients where fixation was done using a cortical button & interference screw in comparison to the cortical button alone.

Conclusion

No significant difference in complication was noted between early and delayed repair. However, more complications were noted in the single anterior incision compared to the two anterior incision technique. Higher complications were also observed with the cortical button and interference screw fixation method compared to the cortical button alone.

Introduction

Distal biceps tendon rupture represents only 3% of all injuries to the biceps and has a reported incidence of 1.2 per 100,000 per year [1]. Male patients between the ages of 30 and 60 are most likely to develop distal biceps tears, and the dominant extremity is frequently affected due to eccentric loading of the muscle–tendon unit [1]. Risk factors include smoking and steroid use [1]. Surgical treatment is generally advised in an active, healthy patient as non-operative management of a complete rupture; patients will lose 21–55% of supination strength, 79% of supination endurance, 10–40% of flexion strength and 30% of flexion endurance [2, 3]. Generally, repair of the distal biceps to the anatomical insertion of the tendon at the radial tuberosity is the accepted surgical treatment. To improve the outcome and avoid surgical complications, various surgical incision types (single anterior, two anterior incisions, or combined anterior and posterior incisions) and fixation techniques (cortical button alone, cortical button and interference screw, or suture anchors) have been described in the literature [4–8].

Distal biceps tendon ruptures are not always promptly diagnosed or referred appropriately and may present to surgeons after a delay. Previous reports showed higher complications after primary surgical repair, but good results, increased strength recovery and patient satisfaction can be obtained in patients delayed 21 days or longer [9–11]. The time of surgery is thought to be an important factor in the management of these injuries.

The present study aimed to compare the complication rate of early (< 21 days) vs delayed (> 21 days) repair and the effect of the types of incision and fixation methods used in the repair of distal biceps tendon rupture.

Methods

We evaluated a total of 87 patients who underwent distal biceps tendon repair at our institution between April 2014 and June 2022. These repairs were performed by five different surgeons with a special interest in shoulder and elbow surgery. All distal biceps repairs where injury surgery interval < 6 months were included in the study. Exclusion criteria included partial rupture, delayed distal biceps tendon repair requiring allograft reconstruction, inadequate medical records and postoperative follow-up of less than 8 weeks.

Patients were divided into ‘Early repair’ (< 21 days) and ‘Delayed repair’ group (> 21 days) based on the timing of surgery. The following preoperative, intraoperative variables and postoperative outcome measures were recorded:

Preoperative variables: patient demographics (age, sex, hand dominance), smoking habits, steroid use, BMI of the patients, ASA, mechanism of injury and injury–surgery interval.

Intraoperative variables: surgical approach/incision, fixation type/technique, tourniquet time and total operating time.

Postoperative outcome measures: hospital stay, types and duration of postoperative immobilisation, postoperative nerve and vascular complications, range of motion, and rates of infection, rupture, reoperation due to complications, HO formation and hardwires-related complications.

The complications were divided into major and minor complications groups [12]. Major complication includes at least one of the following: distal biceps tendon re-rupture, deep infection requiring operative intervention, posterior interosseous nerve (PIN) palsy, proximal radioulnar synostosis, symptomatic (painful or limited range of motion) heterotopic ossification (HO), functional ROM loss treated with surgical intervention (without HO), vascular injury, complex regional pain syndrome (CRPS) or any other postoperative complication that needed reoperation.

The lack of pronation and supination, along with radiologic evidence of a bony bridge between the proximities radius and ulna, has been identified as proximal radioulnar synostosis. Symptomatic HO (non-bridging) may be palpable, locally tender or painful with restricted forearm rotation or elbow range of motion (ROM). Normal functional ROM of the elbow is 30–130 degrees. Deep infection was defined by the clinical need for surgical debridement to control the infection.

The minor complications were noted as lateral antebrachial cutaneous nerve (LABCN) and radial superficial nerve (RSN) paresthesia, postoperative cubital tunnel syndrome, symptomatic (painful or ROM-limiting) HO without repeated operative intervention and superficial infection not requiring reoperation.

Data management was done using Microsoft Excel, and statistical analysis was performed using online Medcalc Software, Belgium. The mean values and standard deviations were calculated for the collected data. Statistical significance was tested using the Fisher exact test, and a p value of < 0.05 was considered statistically significant.

Diagnosis and Surgical Techniques

Diagnosis of distal biceps rupture was confirmed by detailed clinical examination, MRI scan, or ultrasound of the affected arm, depending on the availability of imaging modalities and inconclusive clinical examination. X-rays in two planes were performed to detect avulsion fractures. Five different shoulder and elbow surgeons performed the surgery. Each surgeon used their preferred repair techniques. Surgery was conducted in the supine position under general anaesthesia with or without additional regional block. All tendons were primarily repaired directly to the bicipital tuberosity, regardless of the tear’s chronicity with or without a tourniquet. The majority were repaired by the inlay technique. Types and numbers of surgical incisions used for exposure and repair of tendon incorporated in the study include (1) anterior single longitudinal or transverse incision, (2) anterior single lazy S-shaped incision, (3) two anterior incisions, a second more proximal anterior incision was used to aid in the retrieval of retracted tendon stumps. To reduce the need for a large incision and extensive soft tissue dissection in the antecubital fossa, this additional incision has been made at the surgeon’s discretion. Types of different fixation methods were also recorded, including (1) cortical button (Arthrex) alone, (2) cortical button (Arthrex) and interference screw fixation, or (3) suture anchor. Intraoperative fluoroscopy was used in all cases to check the position of the flipped button.

Postoperative Protocol

Postoperative protocols were variable, specified by each surgeon and carried out by multiple physiotherapists. All patients received a period of immobilisation (hinge elbow brace or above elbow plaster or sling only) followed by repair-specific physical therapy.

Results

Eighty-seven patients who underwent distal biceps tendon repair were evaluated. After excluding 20 cases, 66 patients were included in our study (5 cases of partial rupture, 10 cases of delayed distal biceps tendon repair requiring allograft reconstruction, 3 cases with inadequate medical records and 2 patients lost to follow-up). Thirty-one patients underwent early and thirty-five underwent delayed repair. Overall, the mean patient age was 43.33 ± 9.91 years (range 21–69 years), with 64 (97%) being male. Detailed patient demographics, steroid use, smoking, BMI, ASA, detailed different mechanisms of injury and injury surgery interval between the two groups are shown in Table 1. In most cases (34, 51.5%), the diagnosis was confirmed on clinical examination only, and the remaining patients were with MRI or US scan or both (Table 1). No one had any bony avulsion on the X-ray.

Table 1.

Comparison of patient demographics and different operative variables between early repair (< 21 days) and delayed repair (> 21 days)

	Overall n = 66	Early repair (< 21 days) n = 31	Delayed repair (> 21 days) n = 35	p value
Age				0.1668
Mean	43.33 ± 9.91 years	41.54 ± 9.21 years	44.91 ± 10.24 years
Range	21–69 years	25 to 67 years	21–69 years
Sex				0.3239
Male	64 (97%)	31 (100%)	33 (94.3%)
Female	2 (3%)	0	2 (5.7%)
Side				0.9641
Right	36 (54.5%)	17 (54.8%)	19 (54.3%)
Left	30 (45.5%)	14 (45.2%)	16 (45.7%)
Dominant side involvement	32 (48.5%)	17 (54.8%)	15 (42.9%)	0.3322
Injury–surgery interval
Mean ± SD	33.56 ± 27.19 days	15.41 ± 4.22 days	49.62 ± 28.79 days
Range	7–130 days	7–21 days	22–130 days
< 10 days	3 (4.5%)	3 (9.67%)	NA
10–21 days	28 (42.4%)	28 (90.3%)	NA
21–42 days	19 (28.8%)	NA	19 (54.3%)
> 42 days	16 (24.2%)	NA	16 (45.7%)
Smoker	12 (18.2%)	7 (22.6%)	5 (14.3%)	0.3866
Steroid user	8 (12.1%)	3 (9.7%)	5 (14.3%)	0.5692
BMI > 30	16 (24.2%)	6 (19.4%)	10 (28.6%)	0.3856
ASA				0.9670
I	46 (69.7%)	22 (71%)	24 (68.6%)
II	18 (27.3%)	8 (25.8%)	10 (28.6%)
III	2 (3%)	1 (3.2%)	1 (2.9%)
Mechanism of injury
Fall	8 (12.1%)	4 (12.9%)	4 (11.4%)
Gym	8 (12.1%)	2 (6.5%)	6 (17.1%)
Hyperextension type injury	3 (4.5%)	0	3 (8.6%)
A heavy object fell on the arm	3 (4.5%)	1(3.2%)	2 (5.7%)
Leisure/sports activity	13 (19.7%)	7 (22.6%)	6 (17.1%)
Lifting heavy object	31 (47%)	17 (54.8%)	14 (40%)
Investigation
Ultrasound (US)	13 (19.7%)	5 (16.1%)	8 (22.8%)
MRI	17 (25.8%)	4 (12.9%)	13 (37.1%)
US + MRI	2 (3%)	1 (3.2%)	1 (2.9%)
Tendon retraction (US/MRI report)	22 cases (33.3%) documented	8 cases (25.8%) documented	14 cases (40%) documented	0.0343
Mean	5.61 ± 2.22	4.5 ± 1.66 cm	6.45 ± 2.07 cm
Range	1.5–10 cm	1.5–7.31 cm	6–10 cm
Inpatient admission	4 (6.1%)	1 (3.2%)	3 (8.6%)
Day case procedure	62 (93.9%)	30 (96.8%)	32 (91.4%)
Anaesthesia
GA	59 (89.4%)	28 (90.3%)	31 (88.6%)
GA + regional block	6 (9.1%)	2 (6.5%)	4 (11.4%)
Regional block only	1 (1.5%)	1 (3.2%)	0
Tourniquet used	46 (69.7%)	21(67.7%)	25 (71.4%)	0.003
Duration of tourniquet
Mean ± SD	64.58 ± 22.08 min	52.57 ± 18.79 min	74.68 ± 19.42 min
Range	23–110 min	23–92 min	45–110 min
Duration of operation  Mean ± SD	78.89 ± 23.24 minutes	67.77 ± 19.54 min	88.74 ± 21.77 min	0.0001
Range	35–130 min	35–105 min	53–130 min
Type of incision (single incision technique)
Single longitudinal	24 (36.4%)	10 (32.3%)	14 (40%)	0.6112
Single transverse	10 (15.1%)	8 (25.8%)	2 (5.7%)	0.037
Lazy S-shaped	14 (21.2%)	7 (22.6%)	7 (20%)	1
2X anterior incision	18 (27.3%)	6 (19.4%)	12 (34.3%)	0.268
Technique of fixation
(a) Inlay	62 (94%)	29 (93.5%)	33 (94.3%)	0.133
(b) Onlay	4 (6.1%)	2 (6.5%)	2 (5.7%)	0.222
Methods of fixation
(A) Endobutton only	26 (39.4%)	9 (29%)	17 (48.6%)
(B) Endobutton with interference screw	37 (56%)	20 (64.5%)	17 (48.6%)
(C) Suture Anchor (Twinfix)	1 (1.5%)	1 (3.2%)	0
(D) Togglelok and Ziploop	2 (3%)	1 (3.2%)	1 (2.9%)
Post-op plaster used Duration of plaster	18 (27.3%)	12 (38.7%)	6 (17.1%)	0.303
Mean ± SD	2.16 ± 0.5 weeks	2.08 ± 0.27 weeks	2.33 ± 0.74 weeks
Range	2–4 weeks	2–3 weeks	2–4 weeks
Sling used Duration of sling	59 (89.4%)	27 (87.1%)	32 (91.4%)	0.1407
Mean ± SD Range	4.18 ± 1.59 weeks	3.85 ± 1.32 weeks 2–6 weeks	4.46 ± 1.74 weeks 2–6 weeks
Postoperative brace Duration of Brace	10 (15.2%)	4 (12.9%)	6 (17.1%)	0.336
Mean ± SD Range	6.5 ± 1.36 weeks	7 ± 1.73 weeks 6–10 weeks	6.16 ± 0.89 weeks 5–8 weeks
Follow-up				0.982
Mean ± SD	14.92 ± 7.50	14.9 ± 9.17 weeks	14.94 ± 5.61
Range	8–60 weeks	8–60 weeks	8–30 weeks

A P value of < 0.05 was considered statistically significant

No statistically significant differences were noted (Table 1) between early and delayed repairs in age, sex, smoker, steroid user, BMI, ASA and dominant vs non-dominant side injury.

We compared the results and complications of early (< 21 days from injury) and delayed (> 21 days from injury) distal biceps repair. Thirty-one (47%) patients were operated in less than 21 days of injury, and 35 (53%) patients were operated after 21 days. In the early repair group, the average injury surgery interval was 15.41 ± 4.22 days (range 7–21 days); in the delayed group, it was 49.62 ± 28.79 days (range 22–130 days).

The difference in biceps proximal tendon retraction (on scan) between the two groups is shown in Table 1 and was statistically significant (p = 0.034) between the time of repair and tendon retraction.

Details of different intraoperative variables (types of anaesthesia, use of tourniquet and total operative time) are summarised in Table 1.

Overall, a tourniquet was used in 46 cases (69.6%). It was used in 21 patients (67.7%) in the early repair group with a mean tourniquet time of 52.57 ± 18.79 min (range 23–92 min) and in 25 cases (71.4%) in the delayed repair group with mean tourniquet time of 74.68 ± 19.42 min (range 23–110 min). Tourniquet time was significantly shorter for the early repair group and was statistically significant (p = 0.0003).

Overall, the mean operation time was 78.89 ± 23.24 min (range 35–130 min). Total operation time was significantly shorter for the early repair compared with those for delayed repair (67.77 ± 19.54 min, range 35–105 min vs 88.74 ± 21.77 min, range 53–130 min). This was statistically significant (p = 0.0001).

All patients were treated with a single incision (no dorsal incision) repair technique. Details of different types of incisions are shown in Table 1. The most common incision in both the early (32.3%) and delayed (40%) surgical group was a single longitudinal, and this was followed by a single transverse incision (25.8%) in the early repair group and two anterior incisions (34.3%) in the delayed group.

Overall, most cases (93.9%) were treated by the inlay technique and 6.1% by the onlay technique.

Different fixation techniques are shown in Table 1. The most common (56%) fixation technique was the cortical button plus interference screw. The most common fixation method was the cortical button with interference screw (64.5%), followed by the cortical button alone in nine (29%) early surgical repair group cases. In the delayed group, equal numbers (17, 48.6%) of patients were fixed with the cortical button plus interference screw and cortical button alone (Table 1).

Different types of postoperative immobilisation (arm sling, brace or plaster) and duration are shown in Table 1. The majority (89%) of the patients had arm sling only. There was no statistically significant difference with using postoperative plaster, sling or brace in either group (Table 1). Sixty-two (93.9%) patients were treated as a day case procedure.

The overall average length of follow-up was 14.92 ± 7.50 weeks (range 8–60 weeks). There were no significant differences between the two groups (p = 0.982).

Overall, 36 (54.5%) had some complications, of which 9 (13.6%) had major and 27 (40.9%) had minor complications (Table 2).

Table 2.

Complications following early (< 21 days) and delayed repair (> 21 days)

	Overall n = 66	Early repair (< 21 days) n = 31	Delayed repair (> 21 days) n = 35	p value
Major complications	9 (13.6%)	5 (16.1%)	4 (11.4%)	0.724
Distal biceps re-rupture	1 (1.5%)	1 (3.2%)	0
Posterior interosseous nerve (PIN) palsy	3 (4.5%)	1 (3.2%)	2 (5.7%)
Symptomatic heterotopic ossification (HO)	1 (1.5%)	1 (3.2%)	0
Vascular injury	1 (1.5%)	0	1 (2.9%)
Reoperation due to complication	3 (4.5%)	2 (6.5%)	1 (2.9%)
Minor complications	27 (40.9%)	12 (38.7%)	15 (42.9%)	0.804
Lateral antebrachial cutaneous nerve (LABCN) injury	20 (30.3%)	9 (29%)	11 (31.4%)
Radial superficial nerve (RSN) injury	1 (1.5%)	0	1 (2.9%)
Superficial infection not requiring an operation	5 (7.6%)	2 (6.5%)	3 (8.6%)
Hardwire problem not requiring operation	1 (1.5%)	1 (3.2%)	0
Total complication	36 (54.5%)	17 (54.8%)	19 (54.3%)

Seventeen (54.8%) had complications in the early repair group, and 19 (54.3%) had complications in the delayed group. Details of major and minor complications in both groups are displayed in Table 2. Statistically, no significant difference was noted in major complications (16.1% vs 11.4%, p = 0.724) or minor complications (38.7% vs 42.8%, p = 0.804) between early and delayed repair (Table 2).

In our study, the overall incidence of nerve palsy was 36.36%. The delayed repair group had slightly higher (32.3% vs 40%, p = 0.611) nerve palsy compared to the early repair group.

The most common nerve complication encountered was a transient lateral antebrachial cutaneous nerve (LABCN) palsy (n = 20, 30.3%); there was no significant difference between the two groups (29% vs 31.4%). No patients required exploration or repair of the LABCN; three patients had ongoing sensory symptoms at the time of the last follow-up before discharge. There was one case of SRN involvement, and they recovered fully after 3 weeks. Overall, three patients (4.5%) had PIN palsy, two cases (5.7%) in the delayed group, and one case (3.2%) in the early repair group. Two cases were recovered fully by 6 months, and the third case underwent removal of the cortical button after 3 months due to suspicion of entrapment of the PIN nerve under the button. PIN palsy persisted despite surgery.

The overall rate of postoperative superficial wound infection and wound related problems was 7.6% (early repair, 6.5%; delayed repair, 8.6%). All of them were treated with oral antibiotics. No patients required any surgical debridement.

One (1.5%) had tendon re-rupture 3 months after repair (early repair, cortical button only) following the fall, which was confirmed with an ultrasound scan. This patient had a good function in her arm despite re-rupture and was managed non-operatively.

One patient (1.5%) had a brachial artery injury (cortical button with screw, single longitudinal incision). This patient had biceps repair 58 days after injury. The following day, he was admitted to the hospital with an acute ischaemic arm. He was treated with embolectomy and interposition vein graft by the vascular team. This patient recovered fully without any long-term sequelae due to vascular insult.

There was one case (1.5%) of symptomatic (restricted forearm rotation) heterotopic bone (Fig. 1) formation (HO) in early repair (single lazy s-shaped incision; biceps button with interference screw) group and was treated with excision of ectopic bone at 9 months after primary repair. This patient had associated involvement of LABCN. The patient regained good function after surgery.

Fig. 1.

AP (a) and lateral (b) radiographs showing HO (symptomatic with restriction of forearm rotation) in early repair group after distal biceps tendon repair

One patient (1.5%) in the early repair group had intramedullary migration of cortical button (Toggleloc) from the dorsal cortex (Fig. 2). This happened due to further injury to the elbow after the fall. The tendon was intact on scan and was managed conservatively.

Fig. 2.

AP (a) and lateral (b) radiographs showing intramedullary migration of cortical button after distal biceps repair

Also, higher (68.8% vs 16.7%, p = 0.0002) overall complications were noted in single anterior incision vs two anterior incisions technique (Table 3). Similarly, higher (76.3% vs 25.9%, p = 0.0001) overall complications were noted in patients where fixation was done with a cortical button and interference screw vs cortical button only (Table 4).

Table 3.

Complication rates by single anterior vs two anterior incision exposure

	Single anterior incision (longitudinal/transverse/lazy s-shaped), n = 48	Two anterior incision, n = 18	p value
Major complications	9 (18.8%)	0
Minor complications	24 (50%)	3 (16.7%)
Overall complications	33 (68.8%)	3 (16.7%)	0.0002

A P value of < 0.05 was considered statistically significant

Table 4.

Complication rates by cortical button only vs by cortical button and interference screw fixation method

	Fixation by cortical button only, n = 27	Fixation by cortical button and interference screw, n = 38	p value
Major complications	2 (7.4%)	7 (18.4%)
Minor complications	5 (18.5%)	22 (57.9%)
Overall complications	7 (25.9%)	29 (76.3%)	0.00010

A P value of < 0.05 was considered statistically significant

Overall, three (4.5%) patients had reoperation due to some complications. Two (6.5%) were in the early repair group, and one (2.9%) was in the delayed group.

No patient had any functional limitation of the elbow range of motion during the final follow-up. In our series, no cases of synostosis, proximal radial fracture, or deep infection needed surgery.

Discussion

Although options to treat patients with distal biceps tendon ruptures have continued to evolve over the last several years, the optimal timing of surgery has not been clearly defined. Most surgeons advocate early surgical repair to avoid tendon retraction and soft tissue scarring.

Our study showed no significant difference in major or minor complications between early (< 21 days) and delayed repair (> 21 days) of the distal biceps tendon. We noted more complications in the single anterior incision technique compared to the two anterior incisions technique. Higher complications were also observed with cortical button and interference screw fixation compared to cortical button alone.

Kelly et al. mentioned that most of the morbidity could be primarily related to the time of repair and recommended an early re-fixation. They described an increased complication rate from 24% (0–9 days post-injury) to over 38% (10–21 days post-injury) and 41% in cases of delayed re-fixation (22–1918 days post-injury) [11]. Kelly et al. also noted increased infection, loss of range of motion and HO in the delayed fixation group.

Bisson et al. found a 40% complication rate in patients with distal biceps tendon rupture operated after 2 weeks of injury, compared with 20% after the acute intervention [4]. Cain et al. reported on 198 patients with a 46% rate of complications correlated with delayed treatment of 4 weeks from injury [13]. Haverstock et al. also reported 29% and 63% complications in the acute and delayed groups, respectively. However, 90% of the complications were transient paraesthesia in the delayed group [9]. Dunphy et al. mentioned an overall complication rate of 37% of 784 operative repairs of distal biceps ruptures regardless of surgical approach or technique of repair [14]. According to the literature, there is a clear increase in complications after delayed treatment; most of these are minor complications [9, 10]. Our present study noted an overall complication rate (54.5%) slightly higher than some of the reported literature, and 50% were due to transient LABCN palsy. Overall, major and minor complications were 13.6% and 40.9%, respectively. However, we did not observe any significant difference in overall complications, major or minor complications between the early and delayed repair groups.

Our study observed significantly higher tourniquet and operating time in the delayed group compared to the early repair group. Longer operating time was probably due to proximal retraction of the tendon and scarring of soft tissue in front of the elbow.

In the last few years, there has been little consensus about which technique of incision or fixation is most effective with the least complication for distal biceps tendon ruptures. Several studies compared single vs double-incision (anterior and posterior incision) techniques regarding operative outcomes and complications. There is the potential to provide small benefits in each technique, irrespective of whether it is a single or double incision [3, 15, 16]. Watson et al. have published a systematic review of complication rates for the single-incision and double-incision techniques (23.9% vs 25.7%) without any statistical differences [17].

Improved techniques and implants have gained popularity for single-incision surgery in the last few years. We noted significantly higher complications in single anterior incision (longitudinal, transverse or lazy s-shaped) compared to two anterior incision technique (68.8% vs 16.7%).

Locating the proximally retracted tendon and reattaching it back to the radial tuberosity poses a significant technical challenge With a conventional single anterior incision, especially in cases of delayed repair, it may be difficult to find the retracted end of the tendon, even with excessive soft tissue retraction. Delayed repairs often require an extensive anterior single lazy S-shaped incision and extensive soft tissue dissection close to the neurovascular in the elbow region. Longer incisions and extensive soft tissue dissection could also lead to soft tissue contracture in front of the elbow and poor cosmesis. On the other hand, the two anterior incisions technique is helpful in retrieving retracted tendon stumps without making longer incisions. Inadequate visualisation of the operative field and excessive soft tissue retraction could be the reasons for the increased risk of neurovascular injury and other complications associated with conventional single anterior incision technique.

Noah DeAngelo et al. reported no significant difference in outcome between the single anterior and two anterior incision groups [18].

Dunphy et al. found no difference (39.6% vs 40.3%) in the complication rate between the cortical fixation button alone vs the cortical button with interference screw fixation for distal biceps repair [14].

We noted significantly higher (76.3% vs 25.9%) complications where the tendon was repaired using the cortical button and interference screw vs the cortical button alone. The reason for increased complications associated with the cortical button and interference screw fixation methods compared to the cortical button alone could be multifactorial, including types of incision used, placement of retractor, need for additional procedures (viz. interference screw placement) which in turn can lead to longer tourniquet and operative time and additional complications like interference screw malposition, failure of the screw and loosening of cortical button fixation etc.

Dunphy et al., in an analysis of 784 patients undergoing distal biceps tendon repair, showed an overall neurological complication rate of 26.6%, with 20.6% attributable to the LABCN lesions [14]. In the current literature, the incidence of LABCN lesions varies from 5 to 60% [14, 17, 19, 20].

We observed an overall 36.4% nerve palsy, of which more than 80% are related to transient LABCN palsy. The delayed repair group had slightly higher nerve palsy than the early repair group (40% vs 32.3%). Most injuries to LABCN are transient neuropraxia and typically associated with temporary numbness along the lateral forearm; however, some may persist for years. LABCN transient palsy was the most frequent minor complication in our study (30.3%), and no significant difference was noted between the two groups (Table 2).

LABCN palsy is a common complication of single anterior incision technique [11] and delayed biceps tendon repair [2, 13]. To avoid injury to the LABCN, the nerve should be identified and protected during the anterior approach, particularly in chronic ruptures where adhesions need to be released to allow for further excursion of the tendon for repair.

Our study noted an overall 4.5% incidence of PIN nerve palsy. Injury to PIN can be a major complication of distal biceps repair, which usually resolves without surgical intervention [16, 20]. An error in drill placement, entrapment under a cortical button or dissection of the proximal radius may result in injury to PIN. PIN injury varies from 1 to 10% in the literature [17, 19–22].

Deep dissection of the forearm in full supination and drilling anterior to posterior in a slightly ulnar direction is needed to avoid PIN injury [23]. A wait-and-see approach with baseline electrodiagnostic studies might be used as early as 3 weeks if the PIN was visualised in continuity at the end of the procedure with no hardware impingement. If there is no evidence of re-innervation in serial nerve conduction studies, exploration and neurolysis or nerve reconstruction should be done sooner. Waiting beyond 6 months for exploration, neurolysis and nerve repair will likely lead to poor results.

Injury to superficial radial nerve is observed in 5–10% of repairs. Typically, this injury results in neuropraxia due to excessive lateral retraction within the wound [17]. We noted a 1.5% incidence of SRN palsy.

Vascular injury is a rare but major complication of biceps tendon repair. Samuel. E ford et al. analysed 970 patients with distal biceps tendon repair and reported a 0.2% incidence of vascular injury [12]. One (1.5%) patient in the delayed repair group (single longitudinal incision) had a brachial artery injury during surgery treated successfully with a vascular graft.

The incidence of HO in the literature varies from 2 to 35%, and 4.1% needed revision surgery. In the literature, a higher incidence of HO formation has also been reported when only a cortical button alone is used for fixation [3, 4, 13, 14, 19, 20, 24]. In some case series, the cortical button alone had a higher rate of HO (4.7%) compared to the cortical button plus interference screw (1.4%) and suture anchors (1.9%) with single-incision repair technique [14]. This may be because the screw tendon–bone interface forms a tight seal, preventing HO-forming marrow components from escaping in these patients, necessitating further study. Only symptomatic HO with loss of functional ROM of the elbow or forearm may benefit from reoperation to excise the ectopic bone to improve ROM. Most surgeons do not routinely use formal prophylaxis with radiation therapy or indomethacin. In our series, we noted one case (1.5%) of symptomatic HO in the early repair group (cortical button with interference screw fixation) with restriction of forearm rotation (Fig. 1). He regained full forearm rotation after the excision of HO, as reported in some series [25]. We think that asymptomatic HO was underreported in our series, as patients did not receive routine radiographs past the immediate perioperative period unless they were symptomatic.

Re-rupture is one of the major complications after distal biceps tendon repair, and the incidence rate varies from 0 to 5.6% in the published series, with larger studies reporting rates near 1.5% [3, 4, 7, 12–14, 17, 19, 20]. The lowest re-rupture rate in the single-incision group was in the cortical button plus interference screw group [14]. In our cohort, we had a single case (1.5%) of re-rupture fixed with cortical screw alone, similar to the reported literature.

Wound-related complications can be devastating to patients with distal biceps tendon repair, and incidence varies from 1.5% in early repair and up to 33% in chronic and revision repair [4, 9, 17, 19, 22]. Intravenous antibiotics, hardware removal and debridement of bone and soft tissue may be necessary in case of deep infection, whereas superficial infections are typically treated with oral antibiotics. In our series, 7.6% of the patients had superficial infections and wound complications, and all were treated successfully with oral antibiotics. There was no significant difference between the early and delayed repair groups. (6.5% vs 8.6%).

Ford et al. [12] reported an overall reoperation rate of 4.5% in their series. We noted a similar incidence of 4.5% reoperation rate in our cohort.

We have several limitations to our study. (1) It is a retrospective study that has its own biases and weaknesses—rely on contributing from the surgeon’s adequate patient assessment and documentation of clinical findings. Individual differences in record keeping cannot be controlled, and failure to include the important findings is a potential source of error. (2) Relatively small sample size in each group. (3) Surgical technique variation across five different surgeons. (4) Postoperative rehabilitation protocol was not standard. (5) No long-term follow-up. (6) Some patients may have relocated their care outside this group, and some complications or reoperation due to a complication can be missed. (7) Whether HO was present was not routinely investigated using postoperative radiographs. Therefore, we may have underreported HO. Patients did not return to the clinic for a standardised final outcome visit for strength, ROM and functional outcome score assessment and the full clinical impact of all major and minor complications.

However, the primary purpose of our study was to assess the postoperative complication only. We reviewed the practise of five different orthopaedic surgeons, and our study findings accurately reflect what occurs in everyday practise.

Conclusion

A delay to surgery (> 21 days) in treating distal biceps tendon ruptures can increase the difficulty of dissection, increasing the overall operating time. However, we did not observe any significant difference in major or minor complications between early (< 21 days) and delayed repair (> 21 days) of the distal biceps tendon. Our present study noted an overall complication rate (54.5%) higher than some of the reported literature, and 50% were due to transient LABCN palsy. Overall, major and minor complications were 13.6% and 40.9%, respectively. These findings are important for surgeons to consider and to disclose to patients when deciding on operative repair. We found higher complication rates in the single anterior incision technique in comparison to the two anterior incisions technique. Similarly, higher complications were noted in cases where the tendon was repaired using a cortical button and interference screw compared to a cortical button alone.

Funding

The authors declared that this study received no financial support.

Data availability

Relevant data of the present study is available from the authors at a reasonable request.

Declarations

Conflict of Interest

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

Ethical Approval

An ethics committee approval is not required for this study type.

Informed Consent

No human subjects were used in this study which necessitates informed consent.