LUCL reconstruction of the elbow: clinical midterm results based on the underlying pathogenesis

Over the last decade, lateral ulnar collateral ligament (LUCL) reconstruction has become an established procedure for chronic posterolateral rotatory instability (PLRI) management [1‐8]. PLRI is primarily associated with traumatic lesion of the LUCL and was first described by O’Driscoll in 1991 [9]. Nowadays, however, a variety of atraumatic mechanisms are well known to induce secondary LUCL insufficiency with subsequent PLRI [7, 10‐12]. In the absence of traumatic history, iatrogenic injuries to the lateral ligament complex during debridement of the extensor carpi radialis brevis (ERCB) or multiple corticosteroid injections due to persistent epicondylopathia humeri radialis (EPHR) are mainly reported as reasons for secondary LUCL insufficiency [10, 11, 13, 14].

LUCL insufficiency leads to lateral elbow pain and impairment in the activities of daily living. Besides clinical testing of lateral and posterolateral elbow laxity and radiographic examination (anteroposterior, lateral), MRI scans are recommended to evaluate the lateral ligament complex of the elbow and the extensor muscles as well as to exclude other causes of lateral elbow pain (e.g. loose bodies, hypertrophic humeroradial plica, osteochondral lesions). Nevertheless, in some cases, the differentiation of chronic PLRI remains challenging. Therefore, arthroscopic instability testing could be useful to determine PLRI and indicate secondary stabilization procedures [15]. In the current literature, encouraging results of LUCL reconstruction in chronic PLRI are described [14, 16‐18]. Nevertheless, the effect of the triggering pathogenesis of PLRI on clinical outcomes following LUCL reconstruction is not yet differentiated.

The purpose of the present study was to determine the influence of the pathogenesis (traumatic vs. atraumatic) of PLRI on clinical outcomes after LUCL reconstruction using an ipsilateral triceps tendon autograft. It was hypothesized that LUCL reconstruction in patients suffering from atraumatic PLRI results in superior patient-reported outcomes (PROs), range-of-motion (ROM), and a lower rate of re-instability compared to patients suffering from traumatic PLRI.

Preoperative and postoperative range-of-motion (ROM) was measured using a goniometer [28]. No statistical differences in ROM were found between the groups (Table 2).

The scoring outcomes are summarized in Table 3. Even though overall functional results of the MEPS were rated as good or excellent in 93.5% for both groups, patients in group EPI showed superior results (p = 0.034) (Fig. 4) [29]. Moreover, group EPI showed increased values for the VAS, the PREE, the DASH score and the SEV than group TRAUMA without statistical differences (Table 3).

According to the Beighton score, general joint hyperlaxity did not differ significantly in both groups (p > 0.05) (Table 1) [30]. No statistical differences were found for steroid injections, previous surgeries, re-instability and revision surgeries regarding PROs for both groups (p > 0.05).

In 12.9% of evaluated patients, a revision surgery was required due to different complications. In group EPI, one patient suffered from a deep infection with propioni acnes bacterium and had to undergo multiple debridement. The second patient showed persistent ulnar nerve symptoms and required neurolysis subsequently. In group TRAUMA, one patient also underwent secondary neurolysis of the ulnar nerve. The second patient received an arthroscopic arthrolysis due to elbow stiffness. Thus, the reoperation rate, therefore, was 11.8% in group EPI and 14.3% in group TRAUMA, respectively.

The most important finding of the present study was that the LUCL reconstruction procedure using a triceps tendon autograft, reliably restores posterolateral elbow stability, regardless of the initial pathogenesis. No significant differences with respect to the pathogenesis were seen in ROM, evaluated PROs and the recurrent instability rate. Nevertheless, a slight trend towards better PROs in patients with atraumatic PLRI was observed, however without reaching statistical significance. Solely the MEPS showed a statistically significant difference in favor of an atraumatic pathogenesis, while 93.5% of all evaluated patients obtained good to excellent results.

The present results of predominantly the MEPS are comparable to previously published data just in terms of the MEPS [2, 5, 14]. Jones et al. described a docking technique with palmaris autograft for reconstruction of PLRI in 8 patients; a MEPS of 87.5 was achieved 7.1 years postoperatively [2]. Olsen et al. reported a MEPS of 92 points 44 months after LUCL reconstruction with ipsilateral triceps graft in 18 patients [5]. In the present study, one possible explanation for the slight statistical difference in the MEPS of both groups could be due to the fact that both patients with re-instability were in the traumatic group, depreciating the groups’ mean MEPS through the scores’ stability section. Consequently, the clinical relevance remains debatable.

The underlying pathology of PLRI (traumatic vs. atraumatic LUCL insufficiency) has not yet been subject to detailed investigation. However, one study included both entities (atraumatic and traumatic pathologies) leading to PLRI in the elbow. Sanchez-Sotelo et al. reported of 32 and 12 patients after LUCL reconstruction with palmaris longus autograft and LUCL repair, respectively [27]. PLRI was caused by traumatic events, previous surgeries and described as unknown in 31, 7, and 4 patients, respectively. In contrast to the reported outcomes, Sanchez-Sotelo et al. reported superior results for patients with traumatic PLRI. However, the variety of several surgical techniques used in their study (repair vs. reconstruction) and different pathologies leading to small inhomogeneous comparative groups, renders the results open to interpretation. In the presented series, patients with traumatic PLRI tended to inferior PROs a greater re-instability rate without reaching statistical difference. We assumed that sequalae of the initial traumatic impact of, including posttraumatic osseous deformities and concomitant osteochondral lesions could lead to inferior subjective and objective results and ongoing impairment. For atraumatic reasons of PLRI, previous studies reported a correlation between chronic epicondylitis humeri radialis and steroid injections, leading to secondary insufficiency of the LUCL [10, 11, 13, 14]. Three cases were reported by Kalainov et al. [11], one case example by Chanlalit et al. [31], and 14 cases by Shim et al. [14]. Shim et al. reported significant improvement in functional outcomes and PROs following LUCL reconstruction with ipsilateral palmaris longus autograft. The MEPS and DASH score improved from preoperatively 60 to 91 postoperatively and from 48.0 to 13.5 points, respectively. The presented group of atraumatic patients (n = 14) in the current study achieved slightly better postoperative results in the MEPS with 98.9 ± 3.7, as well as for the DASH score 7.7 ± 11.8. However, preoperative values are not comparable due to missing data in the present study. Overall, recent literature shows good to excellent functional results at mid- to long-term follow-up for 85–90% after surgical restoration of posterolateral elbow stability, irrespective of initial pathology and the used surgical technique [2, 3, 14, 17, 27, 32].

In the present series, two patients indicated re-instability at follow-up survey. Interestingly, both belonged to the traumatic group (group TRAUMA) with accompanying fractures. Reasons for this skew may include altered osseous configuration and chondral lesions, which could lead to persisting micro-instability. The rate of re-instability in group TRAUMA was 14.3%, which is in accordance with the previously published re-instability rates after LUCL reconstruction after posttraumatic PLRI [18]. The aforementioned study by Sanchez-Sotelo reported a re-instability rate of 11% with two out of five patients receiving a revision stabilization procedure. Olsen and Sojbjerg evaluated a series of 18 patients with posttraumatic PLRI and LUCL reconstruction using an ipsilateral triceps tendon autograft [5]. The re-instability rate was 22% in the clinical testing, but only one patient had subjective complaints and underwent reoperation. These findings resemble the results of our study. The re-instability rate following LUCL reconstruction in atraumatic PLRI is rather high with 21.4% [14]. However, Shim et al. also argue that re-stabilization procedures were not necessary due to only mild symptoms [14].

In a systematic review including 8 studies, with 130 patients, the re-instability rate was 8% and the overall complication rate 11% following LUCL reconstruction [18]. These complication and revision rates are comparable to the present study with 12.9% for both groups. Reasons for reoperation were neuritis of the ulnar nerve, deep wound infection and arthrofibrosis.

The main weakness of this study is its retrospective design with a limited sample size. The number of evaluated subjects, however, is comparable to previous studies and a reasonable follow-up rate of 86.1% with a midterm follow-up time was achieved [2, 5, 14, 27, 32, 33]. Furthermore, the study contains distinguishing strengths. First, PLRI was confirmed under direct visualization by arthroscopic testing in all patients. Second, all LUCL reconstruction procedures were performed in a standardized uniform fashion identically (ipsilateral triceps tendon autograft, hybrid fixation technique) minimizing performance bias. Third, a priori power analysis was conducted.

LUCL reconstruction using a triceps tendon autograft for the treatment of PLRI leads to good to excellent clinical outcomes regardless of the underlying pathogenesis (traumatic vs. atraumatic) with a low re-instability rate (6.5%). However, the propensity for re-instability is higher for traumatic PLRI. Moreover, traumatic PLRI tends to result in inferior PROs and clinical outcomes.