Functional outcome of diaphyseal fractures of humerus in adults treated with closed interlocking nails: A prospective study

Aim

The aim of this study is to bring out certain facts which will help in assessing the functional outcome of interlocking nail osteosynthesis for diaphyseal fractures of humerus in adults.

Objectives

Study area

Department of Orthopaedics, Peerless Hospital and B. K. Roy Research Centre, Kolkata - 94, West Bengal. 

Study period

October 2020 to May 2021.

Sample size

This is a prospective clinical study done in the Department of Orthopaedics and traumatology, Peerless Hospital and B.K. Roy Research Centre, Kolkata, from October 2020 to May 2021 on a sample size of 36.

Study population

Adults with diaphyseal fracture of humerus who fulfill the following inclusion criteria were included in the study.

Sample design

The study was conducted among the adult patients attending Orthopaedics out-patient department and emergency of Department of Orthopaedics, Peerless Hospital and B. K. Roy Research Centre, Kolkata - 94, West Bengal with primary isolated fracture of shaft of humerus.

Inclusion criteria

Exclusion criteria

Study design

Institution based prospective study.

Study tools

Parameters to studied

History taking

A detailed and careful history was taken from each patient and their relatives particularly emphasizing on the mode of injury. All the details were documented properly in respective case sheets.

Clinical examination

All patients were thoroughly examined clinically starting from the standard General Survey, Systemic and Local Examination. Methodical examination was done to rule out other fractures and other injuries.

Initial treatment

In all patients fracture was temporarily stabilized with Plaster of Paris U-Slab and arm pouch sling. It was made sure to stabilize the patient optimally and adequate pain management was undertaken. Medications for their existing comorbidities were continued.

Pre-operative evaluation

Standard radiographs (Digital) of the humerus including the shoulder and elbow joint i.e., anteroposterior and lateral views were done. Every patient underwent a standard set of investigations including blood for Hb%, TC, DC, ESR, sugar, urea, creatinine, Coagulation profile, Serum sodium and potassium, pre-op serology, chest x-ray (PA view) and ECG. Other essential investigations depending on the medical condition of the patient were also done.

Anaesthetic and medical clearance

All the surgeries were done after appropriate cardiological and medical evaluation and optimization. Proper pre anaesthetic checkup were done in every patients before posting for surgery.

Counselling and consent

All patients and their relatives were counselled to their satisfaction in their own language about the aim of this study, surgery, advantages and disadvantages, alternatives, possible complications and outcome of various procedures and informed consent were taken. After due consent and medical or anaesthetic clearance, the patients were posted for surgery.

Anaesthesia

General anaesthesia with endotracheal intubation.

Patient positioning and draping

All patients were positioned supine on radiolucent table with shoulder at the edge of bed and C-arm was brought in from foot end .

Nail length and diameter assessment

The length of nail taken 1 cm below the articular margin of humeral head to 2.5 cm above olecranon fossa. Diameter of the narrowest part of medullary canal was estimated with radiographic canal width estimator.

Approach

About 3 cm incision were made at the anterolateral margin of acromion. Subcutaneous tissue incised to expose deltoid fibres which was split to expose supraspinatus. Supraspinatus was sharply incised along the line of fibres and retracted gently to expose head of humerus.

Entry point and guide wire insertion

The guide wire is inserted through the opening in the supraspinatus tendon and entry point is confirmed under image intensifier in 2 planes. The ideal entry point is situated medial to the greater tuberosity, which is lateral to the axis of the medullary canal in the AP view and in line with the axis in the lateral view.

Approach

About 3 cm incision were made at the anterolateral margin of acromion. Subcutaneous tissue incised to expose deltoid fibres which was split to expose supraspinatus. Supraspinatus was sharply incised along the line of fibres and retracted gently to expose head of humerus.

Entry point and guide wire insertion

The guide wire is inserted through the opening in the supraspinatus tendon and entry point is confirmed under image intensifier in 2 planes. The ideal entry point is situated medial to the greater tuberosity, which is lateral to the axis of the medullary canal in the AP view and in line with the axis in the lateral view.

Opening entry portal

The entry portal is opened with cannulated awl over the guide wire.

Nail assembly and insertion

The nail is mounted to insertion handle and Closed reduction done and nail passed through fracture site into the distal fragment, confirming the humeral shaft alignment, rotation and length, taking care that it is not proud proximally. When the medullary canal is too narrow we reamed the canal sequentially before nail insertion. We also used poller screws to aid in reduction.

Interlocking

Proximal interlocking is performed through the insertion handle from lateral to medial. Malrotation and/or distraction at the fracture site were corrected, prior to distal interlocking. Distal interlocking was done by freehand technique from anterior to posterior after splitting biceps and brachialis.

Closure

Supraspinatus tendon was repaired carefully with interrupted absorbable sutures. The deltoid, subcutaneous tissue, and skin are closed in layers separately.

Figure 1

Instruments in tray

Figure 2

Instruments in trolley

After treatment

Postoperatively the patients were asked to move their fingers and wrist joint. Pendular exercises and elbow range of movement exercises to be started from the next day of surgery. Check dressing was done on 3^rd postoperative day. They were prohibited from lifting weight or putting additional stresses on the affected limb. Patients were discharged usually on the 4th post-operative day with the arm in an arm pouch sling and advised to come for sutures removal on 14^th post-operative day.

Follow up

All the patients were followed up at 2 weeks from date of surgery for removal of sutures. Subsequent follow ups were done at 6^th week and then at 6 weeks interval till 6 months, then 3 monthly for next 6 months with a minimum period of 6 months follow up. On the follow up of 6^th week, another X-ray of whole length humerus including shoulder and elbow joint – AP & Lateral view was done to assess the process of union.

Statistical analysis

All data were captured and analysed properly by using appropriate statistical tools. Then the functional outcome were assessed using DASH Score (The Disabilities of the Arm, Shoulder & Hand Score) & Constant-Murley scoring system.

Age distribution

Majority of humerus shaft fractures occurred in age group 21 to 40 years (55.6%). Age is significant in our study and outcome is worse in older age group.

Sex distribution

In our study there were 23 males (63.9%) and 13 females (36.1%) showing male preponderance, but it was statistically not significant in terms of final outcome.

Injury mechanism

In our series the most common mechanism of injury is direct trauma occurring in 25 cases out of 36(69.4%).

Injury mode

Out of 36 humerus fractures in our study, 21 cases (58.3%) were due to Road traffic accidents followed by domestic fall (19.4%). 5 cases were due to fall from height, while rest 3 cases were due to physical assault.

Fracture site

Middle third fracture was most common (55.6%) in our series.

Constant Murley components

Complications

Function outcome

Dash score

Final functional outcome based on DASH Scoring system in our study shows good to excellent results in 32 patients (88.8%) and poor to moderate results in 4 patients (11.1%).

Table 3

	Final Outcome
	Moderate/ Poor	Good/Excellent
	Mean ± Std. Deviation	Mean ± Std. Deviation	P Value	Significance
Age(years)	56 ± 12.83	37 ± 10.04	0.001	Significant
Interval between injury & surgery	4.5 ± 1.73	3.13 ± 1.26	0.056	Not Significant
Duration of hospital stay	6.5 ± 2.38	5.34 ± 2.89	0.450	Not Significant
Pain Score	8.75 ± 2.5	15 ± 0	<0.001	Significant
Unaffected Sleep Score	2 ± 0	2 ± 0		Significant
Full Recreation Score	0 ± 0	3.88 ± 0.71	<0.001	Significant
Full Work Score	1 ± 2	4 ± 0	<0.001	Significant
Strength of Abduction (pounds)	21 ± 3.46	23.5 ± 1.78	0.023	Significant
Abduction (degrees)	82.5 ± 12.58	145.31 ± 17.96	<0.001	Significant
Abduction	4.5 ± 1	8.44 ± 1.41	<0.001	Significant
Forward flexion (degrees)	87.5 ± 17.08	148.44 ± 14.83	<0.001	Significant
Forward flexion	4.5 ± 1	8.69 ± 1.09	<0.001	Significant
Constant Murley score	54.75 ± 7.09	90 ± 6.85	<0.001	Significant
Final DASH score	50.4±13.14	17.00±7.52	<0.001	Significant
Radiological Union (weeks)	18 ± 4.62	15.5 ± 2.83	0.129	Not Significant

Figure 3

Case 1

Figure 4

Case 2

Figure 5

Case 3

Figure 6

Case 4

Figure 7

Case 5

Age incidence

Our results are comparable to studies of Sam G Hunter et al,9 Griend RV et al,10 Changulani M et al.11 So as humerus fracture affects the young and most active age group (20 to 40 years) it is quite justified to return them to their pretrauma status as early as possible through surgical intervention.

Sex incidence

In our study out of 36 patients, 23 were male (63.9%), showing male preponderance in humerus shaft fractures, which is consistent with other studies. The male predominance in the series can be attributed to the fact that most of the traumas were as a result of motor vehicular accidents and fall from height and males are more likely to be involved in such activities.

Side of fracture

As compared to other studies mentioned, left sided humerus fractures appeared to be commoner than the right side. This may be due to human nature of protecting the dominant hand when possible or purely accidental.

In this study the most common mode of injury is the road traffic accident which is similar to other studies. This implies that humerus fracture usually occurs due to high velocity trauma and indirectly implies that most of them are often associated with other injuries or polytrauma.

Level of fracture

Like all the above mentioned studies, in our study also middle third fracture of humerus is most common. In our study 55.6% fractures were in middle third as compared to 60% and 63.9% by H T Tee et al. and Griend RV et al. respectively.

In our study union occurred between 14 to 26 weeks, with a mean union time of 15.7 weeks. Results matches exactly with series of Sahu RL et al. and are comparable with series of Rodriguez-Merchan EC18 and Demirel M et al.14

Union rate

In our series out of 36 patients, there was only one delayed union and no nonunion, thus making the rate of union as 100% with similar results of Klenerman et al.19 and Rodriguez- Merchan EC.18 The delayed union in our study was possibly due to distraction at fracture site, however it united without any intervention.

In our study 88.8% (32 out of 36) had full or good shoulder and elbow movements which can be compared with study of Griend RV et al.

In our study 88.8% has good to excellent shoulder function with a mean Constant Murley Score of 86. Park JY et al also had similar shoulder outcome.

The primary concern in antegrade humeral nailing beside fracture union is shoulder dysfunction. The reasons of the stiffness are protrusion of nail at the entry point, damage to the rotator cuff at the time of nail insertion, inadequate removal of bone debris after nailing and lack of patient’s cooperation with the postoperative rehabilitative regimen. In the present series, out of the 4 patients having shoulder stiffness one patient had protrusion of nail at entry point. Shoulder function improved after removal of nail. The other three were probably due to rotator cuff injury and lack of proper rehabilitation. The average time of return of full shoulder function was six weeks with adequate compliance to the rehabilitation.

Elbow function were excellent in all patients except minimal restriction in 2 patients in our series, which improved with prolonged rehabilitative regime implying that antegrade nailing do not affect elbow function and do not violate normal elbow anatomy.

Our series has 100% union rate with average union time of 15.7 weeks. Only one case of delayed union was found, probably due to mild distraction at fracture site, secondary to larger diameter nail. Eventually it united at 26 weeks of follow up with no intervention.

No cases of infection, superficial or deep, was recorded in our study.

One case of post-operative iatrogenic radial nerve neuropraxia occurred in our study, probably due to traction injury. It recovered fully at 8 weeks with postoperative cock up splint, passive excercises and supervised rehabilitation.

In our study, 88.8% (69.4% excellent and 19.4% good) patients had good to excellent results. This is comparable to most previous studies. Thus, though with limitations antegrade humeral nailing shows overall favourable outcome.