Posttraumatic elbow agility and reduction of muscle force after intra-articular distal fractures of the humerus in adults

Abstract

BACKGROUND:

Treatment of distal intra-articular humerus fractures is still a technical challenge. Until now, little is known about the regain of strength and elbow agility after surgical treatment of these fractures. Due to small collectives there is only limited data.

OBJECTIVE:

Investigation of regained strength and elbow agility in patients with intra-articular distal humerus fractures.

METHODS:

A total of 28 patients were treated with distal intra-articular humerus fractures followed up for an average period of 62.3 months. The following parameters were examined: Arthrosis, heterotopic ossification, functional outcome (MEPS, DASH score, LES) and isometric strength of the elbow in extension and flexion was tested in 30 ${}^{\circ}$ , 60 ${}^{\circ}$ and 90 ${}^{\circ}$ in a custom-made positioning device.

RESULTS

: There was a high complication rate with 32%. At the 60th month post injury, range of motion (ROM) of the elbow was 114 ${}^{\circ}$ with a reduction of 32 ${}^{\circ}$ compared to the contralateral uninjured side ( $p<$ 0.001). The highest reduction was seen in extension with an average loss of 16 ${}^{\circ}$ ( $p<$ 0.001). Loss of motion correlated with the fracture severity regarding the AO-classification ( $r=$ 0.54, $p<$ 0.01). The average regained muscle force was 81.5% in flexion and 92% in extension in comparison to the contralateral healthy side. Patients over 60 years had less range of motion and inferior results in the DASH score compared to younger patients.

CONCLUSIONS:

Functional impairment in terms of reduced ROM and muscle force is a common complication after distal intra-articular humerus fracture. Patients over 60 years have a higher deficit of motion in the injured elbow joint and an inferior clinical outcome. Superiority of modern angle-stable implants could yet not be shown.

Keywords

Distal intra-articular humerus fracture reduction of elbow agility loss of muscle force angle-stable implants

1. Background

Fractures of the distal humerus are rare with 2–3% of all fractures. Approximately 60% of these fractures are intra-articular [1, 2]. Due to the constant aging of the population, the rate of osteoporotic fractures will continue to increase [3, 4]. The goal of surgical treatment should be a free range of motion and a painless function of the joint. The gold standard in the treatment of unstable fractures remains to be surgical with better results than in conservative therapy [2, 5]. Surgical therapy is still a technical challenge, although new innovative anatomical and multidirectional locking plates promise great potential. Nevertheless, the risk of complications remains high. The main complications expected postoperatively are a decrease of the range of motion (ROM), ulnar nerve damage, non-union and heterotopic ossification [3, 4, 6, 7, 8, 9]. Due to the low incidence of this kind of injury, there is very little information in this regard found in the current literature. The overwhelming proportion of patients has a loss of function in the sense of a significantly reduced muscular strength, which is hardly considered in the literature [7, 9, 10].

Therefore, the goal of this study was to investigate the rate of complications, functional impairments in regard to the elbow agility in terms of a reduction of the ROM and the reduction of muscle force following surgical treatment of distal intra-articular humerus fractures.

2. Methods

The study was conducted in compliance with the current laws applying in Germany and follows the Declaration of Helsinki for ethical principles for medical research involving humans. The study was approved by the local ethics committee (250/11). Patients’ verbal and written consent to participate in this study was taken.

The retrospective study only included patients with a unilateral distal intra-articular fracture as a mono injury of the upper extremity which subsequently underwent surgery. Twenty-eight patients of a total of 32 patients (87.5%) were examined. Medical charts were analyzed with regards to specific parameters including age, gender, fracture mechanism, fracture type according to the AO classification [11], operative procedure and complications during the treatment during the hospital stay. At the clinical follow-up the function of the joint was examined and the radiographic findings during the treatment were analyzed for postoperative results. The onset of arthrosis was rated according to the classification of Kellgren and Lawrence [12] and heterotopic ossifications according to Brooker [13]. The subjective functional outcome was evaluated by the Mayo Elbow Performance Score (MEPS) [1], Disabilities of the Arm, Shoulder and Hand Score (DASH) [14] and the Liverpool Elbow Score (LES) [15]. To evaluate the quality of life (QoL) the SF-36 questionnaire was used [16].

ROM of the elbow joint was measured clinically. The isometric strength of flexion and extension was quantified in 30 ${}^{\circ}$ , 60 ${}^{\circ}$ and 90 ${}^{\circ}$ positions of the elbow and neutral position of the forearm using a custom made positioning device with a dynamomter (PCE-FM1000, PCE Instruments Deutschland GmbH, Meschede, Germany). Results of the injured side was compared to the contralateral healthy side which served as a control.

Statistical analysis was carried out using IBM SPSS Statistics (version 20; IBM Deutschland Ltd., Ehningen, Germany). All scale variables were tested for normality with the Shapiro-Wilk test. If normal distribution was given the Student’s $t$ -test was used, otherwise the Mann-Whitney U test for independent samples and the Wilcoxon test for paired matches. Correlations were carried out with the Spearman test.

3. Results

Gender distribution was equal (14 female and 14 male patients). There was a bi-headed curve for the age of the patients at the time of injury with one peak at 25 years and another peak at 65 years (Fig. 1). The average age at the time of injury was 52.6 years (range 20–82 years). Patients were followed up at 62.3 months (range 24–104 months) post injury. There were 7 type B-fractures and 21 type C-fractures according to the AO-classification [11] with 15 injuries belonging to the subgroup C-3 (Fig. 2). There were 9 fractures on the left side and 19 on the right side. In 11 patients the dominant arm was injured. Causes of injury included 8 high-energy traumas, 11 moderate traumas and 9 low-energy traumas. Seven fractures (25%) were open fractures (2 $\times$ I ${}^{\circ}$ , 4 $\times$ II ${}^{\circ}$ , 1 $\times$ IIIa ${}^{\circ}$ ) according to the Gustilo classification [17]. One patient showed dysaesthesia of the ulnar nerve upon arrival. Younger patients sustained more often a high-energy trauma with a more severe fracture type according to the AO classification ( $p<$ 0.02).

Figure 1.

Clinical setup for strength-measurement.

Figure 2.

Age and gender distrubution at time of injury.

Figure 3.

a. AP and lateral x-ray of a distal humerus fracture classified by AO/OTA as 13C3. b. Postoperative x-rays (ap and lateral) of the distal humerus fracture (AO/OTA 13C3) treated with double plating osteosynthesis (angle stable implants). c. AP and lateral x-ray of a distal humerus fracture classified by AO/OTA as 13C2. d. Postoperative x-rays (ap and lateral) of the distal humerus fracture (AO/OTA 13C2) treated with double plating osteosynthesis (conventional implants).

All patients were treated operatively: 5 patients received osteosynthesis by screw or pin fixation only, in 23 patients a plate osteosynthesis was carried out (3 $\times$ singular plate, 20 $\times$ double plating) through a standard dorsal approach. Fifteen patients were treated with an angle stable plate osteosynthesis (Fig. 3a and b) and eight patients were treated with conventional plates (Fig. 3c and d). Operation took place after a mean of 2 days (range 0–9 days). Average operation time was 139 minutes (range 41–272 minutes). Patients were hospitalized for an average of 9 days (range 2–24 days). Postoperative immobilization for soft tissues protection was carried out for 3 days in 22 patients whereas in 6 patients immobilisation was carried out for 7 days due to critical condition of the soft tissues.

There was a high rate of complications (9 patients, 32.1%). In 4 patients (14.3%) surgical revision was necessary. One patient suffered of superficial wound infection. In 4 patients the ulnar nerve was irritated and in 1 of these patients a sensible neuropathy still remained at the follow-up. 14.3% (4 patients) had a non-union including 2 implant failures (7.1%) which had to be surgically revised. After, full bony consolidation was seen.

In 20 patients reduction of the articular surface of the distal humerus was anatomical, in five cases there was an intra-articular step of 1–3 mm and in 2 cases a step of $>$ 3 mm could be seen. Six patients (21.4%) had to undergo open arthrolysis during further treatment because of a restricted motion of the elbow.

Radiologically, heterotopic ossification could be seen in 4 patients (2 $\times$ I ${}^{\circ}$ open fracture, 1 $\times$ II ${}^{\circ}$ open fracture, 1 $\times$ III ${}^{\circ}$ open fracture) without the necessity of a reoperation. There were no signs of posttraumatic arthrosis in 14 patients. Seven patients had a I ${}^{\circ}$ arthrosis and 3 patients a III ${}^{\circ}$ arthrosis. There was no case with a IV ${}^{\circ}$ arthrosis. A non-anatomical reconstruction of the joint surface correlated with the onset of a posttraumatic arthrosis ( $r=$ 0.71; $p<$ 0.01).

ROM on the injured side was reduced to 114.1 ${}^{\circ}$ (range 75–160 ${}^{\circ}$ ) (extension/flexion). In contrast, ROM of the contralateral healthy non injured side was 143.9 ${}^{\circ}$ (range 120–160 ${}^{\circ}$ ) (extension/flexion) which implies a reduction of 32.2 ${}^{\circ}$ (0–70 ${}^{\circ}$ ) ( $p<$ 0.01) as a result of posttraumatic reduction of function. The highest reduction of ROM was found in extension with an average loss of 16.1 ${}^{\circ}$ ( $\pm$ 10.8 ${}^{\circ}$ ) ( $p<$ 0.001) followed by a loss of flexion with an average of 13.8 ${}^{\circ}$ ( $\pm$ 13.1 ${}^{\circ}$ ) ( $p<$ 0.001). Besides, reduction of ROM was seen in pronation with an average of 8.9 ${}^{\circ}$ ( $\pm$ 11.0 ${}^{\circ}$ ) ( $p<$ 0.001) und supination with an average of 2.8 ${}^{\circ}$ ( $\pm$ 12.5 ${}^{\circ}$ ) ( $p=$ 0.26). Reduction of ROM correlated to the fracture severity regarding to the AO-classification ( $r=$ 0.54, $p<$ 0.01).

For muscle force measurement the contralateral healthy side was defined as the control with 100%. The average maximum extension force was 87.9% in 30 ${}^{\circ}$ extension ( $\pm$ 27.2%) ( $p=$ 0.035), 87.7% in 60 ${}^{\circ}$ extension ( $\pm$ 34%) ( $p<$ 0.082) and 91.7% in 90 ${}^{\circ}$ extension ( $\pm$ 26%) ( $p<$ 0.121). The average maximum force in flexion was 86% in 30 ${}^{\circ}$ ( $\pm$ 18.7%) ( $p=$ 0.001), 82.9% in 60 ${}^{\circ}$ flexion ( $\pm$ 19.3%) ( $p<$ 0.001) and 81.5% in 90 ${}^{\circ}$ flexion ( $\pm$ 19.1%) ( $p<$ 0.001) (Fig. 4).

Figure 4.

Fracture type distribution according to the AO-classification.

Figure 5.

Average muscle force (extension/flexion in 30 ${}^{\circ}$ , 60 ${}^{\circ}$ and 90 ${}^{\circ}$ ).

MAYO score revealed 87.1 ( $\pm$ 16.9) points, DASH score 16.8 ( $\pm$ 18.3) points and LES 8 ( $\pm$ 1.5) points. Furthermore, there was a correlation inbetween all three questionnaires ( $r=$ 0.746 to $r=$ 0.948; $p<$ 0.001). Besides, a correlation could be seen in regard to a restricted ROM and the results of the questionnaires (MAYO $r=-$ 0.71, $p<$ 0.001; DASH $r=$ 0.87, $p<$ 0.001; LES $r=-$ 0.92, $p<$ 0.001) as well as inbetween the reduction of strength in flexion and the results in the questionnaires (MAYO $r=-$ 0.75, $p<$ 0.001; DASH $r=$ 0.67, $p<$ 0.001; LES $r=$ 0.71 m $p<$ 0.001) (Figs 5–7).

Figure 6.

Correlations between outome (scores) and loss of flexion.

Figure 7.

Correlations between outcome (scores) and reduction of muscle force.

Quality of life measured by the SF-36 questionnaire was reduced with a physical health of 46.1 ( $\pm$ 13.2) points and a mental health of 50.3 ( $\pm$ 12.3) points. A negative correlation could be seen inbetween patient’s age and physical functioning with $r=-$ 0.54 ( $p<$ 0.05). There was no difference inbetween locking plate osteosynthesis compared to conventional plate osteosynthesis.

There were differences in age distribution. In patients with more than 60 years of age ( $n=$ 12) a higher reduction of ROM could be seen compared to younger patients ( $<$ 60 years, $n=$ 16). In addition, elderly patients often had a low energy trauma ( $p<$ 0.01) compared to younger patients. Reduction of ROM in elderly patients was 38.3 ${}^{\circ}$ ( $\pm$ 13.2 ${}^{\circ}$ ) compared to 24.1 ${}^{\circ}$ ( $\pm$ 20.7 ${}^{\circ}$ ) in younger patients. Moreover, the DASH score was higher at 19.5 ( $\pm$ 19.5) points compared to 14.3 ( $\pm$ 21.7) points in younger patients ( $p<$ 0.05).

4. Discussion

Open reduction and internal fixation still remains the gold standard for the majority of distal intra-articular humerus fractures in order to restore the anatomy of the joint and in regard to the best possible function of the elbow joint [18, 19, 20]. The main benefit of operative treatment is the possibility of an anatomical reconstruction of the joint surface and the possibility of a timely postoperative functional treatment to reduce posttraumatic arthrofibrosis [6, 9].

Reconstruction of the radial and ulnar column by double plating is done in most of the cases. Due to the low incidence of these injuries there is only limited data on the functional results in the literature with rather small and often heterogeneous cohorts. Not only in osteoporotic bone multidirectional fixed-angle implants seem to be biomechanically superior. But until now, the clear advantage of these implants in distal intra-articular humerus fractures could not be demonstrated, especially in regard to the restoration of muscle force [2]. In contrast, regarding to Kaiser et al. [21] no complications like non-unions, loss of reposition or infection in a sub-analysis of ten patients over 60 years with a type C-3 fracture could be seen. The follow-up included 7 patients with MEPS of 86 points which was similar to the outcome of younger patients. Schmidt-Horlohé et al. [22] published results of their follow-up with 44 patients including 45 fractures 13 months post injury. In this study MEPS of the patients was 87.5 points with a DASH score of 14.2 points. Average ROM was 110 ${}^{\circ}$ with an extension deficit of 10 ${}^{\circ}$ and a maximal flexion of 127.5 ${}^{\circ}$ . In addition, Kundel et al. [23] included 77 patients in their follow-up who were operatively treated for distal intra-articular humerus fractures after a mean of 3.4 years. Complication rates were high with 24.7% of the patients needing reoperation for arthrolysis. Beyond that, they had a non-union rate of 10.4% and an infection rate of 10%. Functional outcome was good or excellent in 52%. Gupta and Khanchandani [24] analyzed the functional outcome of 55 patients with intercondylar fractures of the distal humerus after a mean of 4 years postoperatively. 25.5% of the fractures met the criteria for type C3.3 fractures. Overall, patients had good and excellent results in 80%. Soon et al. [25] report about 15 patients with distal intra-arcticular humerus fractures who were followed-up after 12.3 months. Good and excellent results in MES were achieved in 87%. Reoperation had to be done in 13.3% for open arthrolysis.

In accordance to the results of the current literature we can confirm that 71.4% of the patients had good to excellent results (MEPS $=$ 87.1 points). But there are limitations in the larger majority of the studies as they only describe the clinical outcome by using performing scores. In contrast, we could show that there was a high correlation inbetween the MES, DASH-score and LES and the functional outcome in terms of reduction of ROM. Furthermore, our collective was homogeneous as we just included patients with a singular injury of the distal humerus.

There is very limited data on reduction of force after distal humerus fractures. To our knowledge there are only two studies in the current literature with a partially comparable setup: Greiner et al. [7] showed similar results in 14 cases of AO type B- and C injuries with a flexion force of 75.3% and an extension force of 70.7% in a 90 ${}^{\circ}$ position of the elbow. However, the study group is heterogenous as some of their patients suffered from concomitant injuries of the ipsi- or contralateral upper extremity. Theivendran et al. [10] published results of 15 patients with bicondylar type-A and -C fractures with a strength of 72% in flexion and 70% in extension. Patients were treated with a double osteosynthesis with locking plates. It remains unclear if forces by abduction of the wrist were excluded in this study which seems to be a limitation.

In our study this particular bias was excluded by positioning the sensor just proximal to the ulnar head in a neutral position of the forearm. Overall, our results show a slightly reduced strength compared to the other studies with a flexion force of 81.5% and a extension force of 91.7%.

Limitation of the study: This is a retrospective study with a relatively small collective of patients although our collective is homogenous compared to other study setups. As there is still a lack of data showing the advantage of angle stable implants in distal intra-articular humerus fractures, a prospective randomized study is desirable.

5. Conclusion

Functional impairment in terms of reduced ROM and muscle force is a common complication after distal intra-articular humerus fracture. Patients older than 60 years have a higher deficit of motion in the injured elbow joint and an inferior clinical outcome. Superiority of modern angle-stable implants could yet not be shown.

Footnotes

Acknowledgments

This publication was funded by the German Research Foundation (DFG) and the University of Wuerzburg in the funding program Open Access Publishing.

Conflict of interest

All ICMJE Conflict of Interest Forms are on file with the publication and can be viewed on request. There are no conflicting interests that are related to the work submitted for consideration of publication.

References

Morrey

. Surgical Exposures of the Elbow. In: Morrey’s The Elbow and Its Disorders. Elsevier; 2009. pp. 115–42.

Robinson

Hill

RMF

Jacobs

Dall

Court-Brown

. Adult distal humeral metaphyseal fractures: epidemiology and results of treatment. J Orthop Trauma. 2003 Jan; 17(1): 38–47.

Puchwein

Wildburger

Archan

Guschl

Tanzer

Gumpert

. Outcome of type C (AO) distal humeral fractures: follow-up of 22 patients with bicolumnar plating osteosynthesis. Journal of Shoulder and Elbow Surgery. 2011 Jun; 20(4): 631–6.

Reising

Hauschild

Strohm

Suedkamp

. Stabilisation of articular fractures of the distal humerus: Early experience with a novel perpendicular plate system. Injury. 2009 Jun; 40(6): 611–7.

Nauth

McKee

Ristevski

Hall

Schemitsch

. Distal humeral fractures in adults. The Journal of Bone and Joint Surgery. 2011 Apr; 93(7): 686–700.

Korner

Lill

Müller

Hessmann

Kopf

Goldhahn

, et al. Distal humerus fractures in elderly patients: results after open reduction and internal fixation. Osteoporosis International. Springer-Verlag. 2004 Oct 29; 16(S02): S73–9.

Greiner

Haas

Bail

. Outcome after open reduction and angular stable internal fixation for supra-intercondylar fractures of the distal humerus: preliminary results with the LCP distal humerus system. Arch Orthop Trauma Surg. 2007 Aug 23; 128(7): 723–9.

Liu

J-J

Ruan

H-J

Wang

J-G

Fan

C-Y

Zeng

B-F

. Double-column fixation for type C fractures of the distal humerus in the elderly. Journal of Shoulder and Elbow Surgery. 2009 Jul; 18(4): 646–51.

McKee

Wilson

Winston

Schemitsch

Richards

. Functional outcome following surgical treatment of intra-articular distal humeral fractures through a posterior approach. The Journal of Bone and Joint Surgery. 2000 Dec; 82(12): 1701–7.

10.

Theivendran

Duggan

Deshmukh

. Surgical treatment of complex distal humeral fractures: functional outcome after internal fixation using precontoured anatomic plates. Journal of Shoulder and Elbow Surgery. 2010 Jun; 19(4): 524–32.

11.

Buckley

Moran

Apivatthakakul

, eds. AO Principles of Fracture Management. In: AO Principles of Fracture Management. Third Edition. Stuttgart: Georg Thieme Verlag; 2018. (Vol. 1: Principles, Vol. 2: Specific fractures).

12.

Kellgren

Lawrence

. Radiological assessment of osteo-arthrosis. Annals of the Rheumatic Diseases. 1957 Dec 1; 16(4): 494–502.

13.

Brooker

Bowerman

Robinson

Riley

. Ectopic ossification following total hip replacement. Incidence and a method of classification. J Bone Joint Surg Am [Internet]. 1973 Dec; 55(8): 1629–32. Available from: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=4217797&retmode=ref&cmd=prlinks.

14.

Jester

Harth

Wind

Germann

Sauerbier

. Disabilities of the Arm, Shoulder and Hand (Dash) Questionnaire: Determining Functional Activity Profiles in Patients with Upper Extremity Disorders. J Hand Surg Br. SAGE PublicationsSage UK: London, England; 2016 Aug 29; 30(1): 23–8.

15.

Sathyamoorthy

. Development and validation of an elbow score. Rheumatology. 2004 Nov 1; 43(11): 1434–40.

16.

Morfeld

Stritter

Bullinger

. 3 Der SF-36 Health Survey. In: Gesundheitsökonomische Evaluationen. Berlin, Heidelberg: Springer Berlin Heidelberg; 2011. pp. 393–410.

17.

Gustilo

Mendoza

Williams

. Problems in the management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma. 1984 Aug; 24(8): 742–6.

18.

Galano

Ahmad

Levine

. Current treatment strategies for bicolumnar distal humerus fractures. Journal of the American Academy of Orthopaedic Surgeons. 2010 Jan; 18(1): 20–30.

19.

Goel

Pike

Athwal

. Open reduction and internal fixation of distal humerus fractures. Operative Techniques in Orthopaedics. 2010 Mar; 20(1): 24–33.

20.

Anglen

. Distal humerus fractures. Journal of the American Academy of Orthopaedic Surgeons. 2005 Sep; 13(5): 291–7.

21.

Kaiser

Brunner

Hohendorff

Ulmar

Babst

. Treatment of supra- and intra-articular fractures of the distal humerus with the LCP Distal Humerus Plate: a 2-year follow-up. Journal of Shoulder and Elbow Surgery. 2011 Mar; 20(2): 206–12.

22.

Schmidt-Horlohé

Bonk

Wilde

Becker

Hoffmann

. Promising results after the treatment of simple and complex distal humerus type C fractures by angular-stable double-plate osteosynthesis. Orthopaedics & Traumatology: Surgery & Research. 2013 Sep; 99(5): 531–41.

23.

Kundel

Braun

Wieberneit

Rüter

. Intraarticular distal humerus fractures. Factors affecting functional outcome. Clinical Orthopaedics and Related Research. 1996 Nov; 332(332): 200–8.

24.

Gupta

Khanchandani

. Intercondylar fractures of the distal humerus in adults: a critical analysis of 55 cases. Injury. 2002 Jul; 33(6): 511–5.

25.

Soon

Chan

Low

. Surgical fixation of intra-articular fractures of the distal humerus in adults. Injury. 2004 Jan; 35(1): 44–54.