Journal of Current Research in Scientific Medicine

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 6  |  Issue : 2  |  Page : 114--122

Antegrade intramedullary interlocking nailing for midshaft humerus fractures: A retrospective study evaluating functional and radiological outcome


Shishir Murugharaj Suranigi, Lingaraj Reddy, Syed Najimudeen 
 Department of Orthopaedics, Pondicherry Institute of Medical Sciences, Puducherry, India

Correspondence Address:
Shishir Murugharaj Suranigi
Professor, Department of Orthopaedics, Subbaiah Institute of Medical Sciences, NH-13, Purle, Shivamogga, Karnataka - 577 222
India

Abstract

Background: The incidence of humeral shaft fracture has significantly increased during the past decade due to the rising population and the number of road traffic accidents. Numerous surgical implants have been devised in order to achieve a stable fixation and early mobilization. Plating is considered as the gold standard for humerus shaft fracture fixation. With the advancement in nailing techniques and newer nail design, there is a shift of trend in the treatment of diaphyseal fractures towards use of nails by the trauma surgeons. The aim of this study was to evaluate the functional outcome of acute humeral shaft fractures undergoing fixation by intramedullary interlocking (IMIL) nails. Materials and Methods: 52 patients (mean age: 29.42 years) with acutely displaced midshaft humeral fractures who underwent intramedullary nailing (Sharma antegrade IMIL Humeral Nail) were retrospectively studied. They were assessed radiologically for fracture union and functional outcome using Constant and Murley Shoulder Score, American shoulder and Elbow Surgeons (ASES) score, and Mayo Elbow Performance score. Results: The mean Constant–Murley score and ASES score at a mean follow-up period of 4.6 years (range: 1–11.3 years) were 87.4 ± 11.2 and 92 ± 1.45, respectively. Out of 52 patients, 6 patients had shoulder impingement, 3 delayed union, 1 had nonunion, and 1 periarthritis of shoulder. Conclusion: Intramedullary nail fixation in the humeral shaft fracture is a minimally invasive procedure with excellent functional and radiological outcome. The results are comparable with that of plating which is considered as the gold standard.



How to cite this article:
Suranigi SM, Reddy L, Najimudeen S. Antegrade intramedullary interlocking nailing for midshaft humerus fractures: A retrospective study evaluating functional and radiological outcome.J Curr Res Sci Med 2020;6:114-122


How to cite this URL:
Suranigi SM, Reddy L, Najimudeen S. Antegrade intramedullary interlocking nailing for midshaft humerus fractures: A retrospective study evaluating functional and radiological outcome. J Curr Res Sci Med [serial online] 2020 [cited 2023 Jan 31 ];6:114-122
Available from: https://www.jcrsmed.org/text.asp?2020/6/2/114/304208


Full Text





 Introduction



Humeral diaphyseal fractures account for 3%–5% of all fractures.[1] About two decades ago, nonoperative management was the treatment of choice for middle third humerus shaft fractures because of the excellent blood supply from the surrounding muscles. Later, rush rod and Küntscher nail came into use, but due to inadequate stability and biomechanical failure, their use was discouraged.[2] When surgical treatment is indicated, compression plating offers the best outcome, but at the cost of extensive dissection, iatrogenic radial nerve injury, an increased risk of infection, and nonunion.[3] Intramedullary fixation has gained popularity over the years as it is less invasive and offers excellent stability. Treatment of femoral and tibial shaft fractures has been very successful with closed locked nailing. However, because of the complex anatomy, nonweight-bearing characteristics, and unique biomechanical properties of the humerus, they do not produce similar results when treated by interlocking nailing.[4] Hence, in this study, we present our experience with treatment of humerus diaphyseal fractures with intramedullary interlocking (IMIL) nails. The aim of this study was to evaluate the functional and radiological outcome of acute humeral shaft fractures undergoing fixation by IMIL nailing.

 Materials and Methods



This was a retrospective study involving patients who underwent IMIL nailing for midshaft humerus fractures between January 2005 and December 2016 with a minimum follow-up of 1 year. The study was approved by the institutional medical ethics committee (IEC: RC/17/28). Written informed consent was taken from all the patients who agreed to participate in this study when they visited the orthopedic outpatient (OP) for follow-up. Patients were contacted via telephone, E-mails, and letters to come for follow-up. A pro forma was used to collect the relevant history, clinical data, and operative details of all the patients who underwent IMIL nailing for humerus shaft fractures from the inpatient files. Details of postoperative wound healing and progress of fracture union, complications if any, functional status of the elbow and shoulder, and radiological bony union were obtained from the OP files. All the patients were operated by a single team of doctors comprising a professor, an associate professor, an assistant professor, and two senior residents.

Functional outcome was assessed using the American Shoulder and Elbow Surgeons (ASES), Constant and Murley score, and Mayo elbow performance score. Radiological union was defined as continuity of 3 out of 4 bony cortices.

A total of 52 patients with midshaft humerus fracture between the age group 19 and 52 years (mean age: 29.42 ± 10.14) years who underwent antegrade humerus nailing for midshaft fractures who fulfilled the inclusion criteria were included in the study. Diaphyseal humerus fracture was defined as fractures of the humerus located 1 inch distal to the surgical neck of humerus and 2 inches proximal to the olecranon fossa. Open fractures, fractures >7 days, pathological fractures, refracture, fractures associated with metabolic bone disease, and polytrauma were excluded from this study. Written informed consent was obtained from all the patients at the time of assessment. Closed fractures were categorized on radiographs according to AO classification. The different fracture patterns were 12A1 (n = 14), 12A2 (n = 18), 12A3 (n = 4), 12B1 (n = 5), 12B2 (n = 9), and 12C2 (n = 2) [Table 1]. No control group was used in this study.{Table 1}

Surgical procedure

Standard surgical procedure for humerus nailing (antegrade interlocking nails from Sharma Surgicals) was followed using image intensifier with the patient in supine position under general anesthesia [Figure 1]a. A longitudinal skin incision 2–3 cm from the anterolateral edge of the acromion, distally toward the deltoid insertion, was made. Subcutaneous tissue was incised sharply. The deltoid muscle fibers were split and retracted. The supraspinatus tendon was incised sharply in line with its fibers with pointed scalpel blade. The edges of the incision are retracted by stay sutures. Entry point was made using an awl just medial to the tip of the greater tuberosity, 0.5 cm posterior to bicipital groove [Figure 1]c and [Figure 1]d. In cases of proximal shaft fractures, in order to correct the rotated proximal fragment, a bicortical 3.5 mm Schanz pin was placed in the proximal fracture fragment [Figure 1]b. This also helped in stabilizing the fragment when making the entry point with an awl. Guidewire was passed after achieving closed reduction of the fracture [Figure 1]e and [Figure 1]f. The length of the nail was measured by subtracting exposed guidewire from the total length of the guidewire. The Schanz pin was then withdrawn to make it unicortical to facilitate the reaming and nail passage [Figure 1]g and [Figure 1]h. We seldom reamed the medullary canal. Reaming was done only when we had difficulty in passing of a 7 mm nail [Figure 1]i and [Figure 1]j. Out of the 52 cases, the fracture in 39 patients was fixed with 7 mm nail while the rest required 8 mm nail. While maintaining the reduction, guidewire was removed, and the nail of proper length and diameter was passed till its proximal end was seen buried beneath the bone by 5 mm to avoid subacromial impingement. This was achieved using an image intensifier. Distal interlocking was performed by a free-hand technique. We always did a midline mini-incision, bluntly dissecting the biceps, and brachialis muscle fibers along with the neurovascular bundle to prevent any damage to them. Furthermore, the narrow locking holes of humeral nails, thin drill bits, and the “slippery” bony surface at the distal humerus make distal interlocking even more challenging. Two anteroposterior locking bolts were inserted with the help of image intensifier [Figure 1]k. The fracture was then reduced by back hammering the nail to compress the fracture site. Proximal locking was then performed. All cases were fixed with 2 proximal locking screws (1 dynamic and 1 static). Blunt dissection of the soft tissues and use of the sleeve system touching the bone helped prevent injury to axillary nerve during the drilling procedure [Figure 1]l and [Figure 1]m. After the procedure, the supraspinatus tendon was meticulously repaired to prevent any postoperative rotator cuff arthropathy. Postoperatively, the limb was kept in an arm pouch. Shoulder pendulum exercises were started immediate postoperative. After surgery, the patient was put on an arm sling.{Figure 1}

All patients were started on passive shoulder mobilization and active elbow mobilization exercises on the 2nd postoperative day. Active overhead shoulder mobilization was started 3 weeks after surgery. Arm sling was discontinued 6 weeks post surgery.

 Results



The mean age of these 52 included cases of IMIL nailing of humerus was 29.42 years (range: 19–52 years). The most common mode of injury was road traffic accident (n = 40), followed by injury due to fall (n = 10). The mean operative time for nailing was 65.56 min with average blood loss of 50.45 ml. The mean duration of hospital stay was 5.89 days.

Out of the 52 cases, in 48 cases, the fracture united with a mean duration of 13.4 weeks (range: 12–16 weeks) [Figure 2], [Figure 3], [Figure 4], [Figure 5]. Two fractures (one transverse and one oblique fracture) needed dynamization and bone marrow infiltration for union. Both these fractures united without any further intervention at 20 weeks and 24 weeks of follow-up, respectively. The mean duration at the time of follow-up was 4.6 years (range: 1–11.3 years) [Table 2].{Figure 2}{Figure 3}{Figure 4}{Figure 5}{Table 2}

Shoulder evaluation was done using Constant and Murley score and graded as excellent (n = 40), good (n = 10), and fair (n = 2). The elbow assessment was done using Mayo Elbow Performance score and graded as excellent (n = 44), good (n = 6), and fair (n = 2). The mean ASES score was 92 ± 1.45 at the time of follow-up [Table 3].{Table 3}

We noted a few complications mentioned in our OP records, which are represented in [Table 4]. One case developed periarthritis of shoulder 1-year postsurgery, which subsequently improved with physiotherapy. The patient was a known case of diabetes under regular treatment with good glycemic control. There was one case of hypertrophic type of nonunion noted at 4 months of follow-up [Figure 6]. On subsequent questioning it, we found out that the patient was a chronic smoker. He underwent nail removal, excision of nonunion ends, plating, and bone grafting. Fracture subsequently united without any further complications after 5 months of plating. Postoperative radial nerve neuropraxia was noted in one case. The patient was put on a dynamic cock-up splint, and the alternate day, radial nerve electrical stimulation was given. The patient had complete recovery at 6 weeks of follow-up.{Table 4}{Figure 6}

Any fracture that united after 16 weeks of surgery was considered as delayed union. In our study, we witnessed three cases of delayed union, all of which were due to initial fracture distraction. Two out of these three cases needed dynamization and bone marrow infiltration for union. Patients were advised overhead weight lifting with 2–3 kg dumbbells, 15 min session, 5–6 times daily postdynamization for fracture union. These fractures united without any further intervention at 20 weeks and 24 weeks of follow-up, respectively. One patient underwent iliac bone grafting at 14 weeks as the fracture showed early signs of nonunion. Fracture united without any further complications at 22 weeks of follow-up [Figure 7].{Figure 7}

Implant exit was not advised routinely for patients. Six patients who had shoulder impingement due to nail prominence proximally underwent nail removal at an average follow-up duration of 22.4 weeks (range: 14–30 weeks).

 Discussion



Among all the skeletal injuries encountered by orthopedic surgeons, humeral fractures account for 3%–5%.[1] The treatment modalities are varied, ranging from closed reduction and casting to operative methods. Conservative management claims superiority over surgical fixation, but has limited value when it comes to obese patients, comminuted fractures, segmental fractures, pathological fractures, and those patients who are not compliant with conservative treatment.[5] IMIL nailing has the advantage of preserving the fracture hematoma, retaining the periosteal blood supply, and load-sharing mechanical properties (biomechanically superior when compared to plating) that provide relative stability resulting in micromotion at the fracture. The downside is that it is technically more demanding and has a steeper learning curve.[6],[7],[8],[9],[10] IMIL nail reduces the effects of stress shielding at the fracture site and lowers the incidence of refracture after implant removal.[11],[12],[13]

Plating has been the gold standard for humerus shaft fracture fixation. Plating accounts for a stable fixation and direct visualization, which is known to provide an accurate anatomic reduction and protection of the radial nerve. IMIL nailing is comparable to plating in terms of iatrogenic radial nerve palsies. In IMIL nailing procedure, the iatrogenic stretching of the radial nerve during antegrade nailing with the use of a mallet might account for the iatrogenic radial nerve injury, but the fact that IMIL nailing has the advantage of preventing exposure and soft-tissue stripping makes this method preferable over plate fixation for surgeons.[4]

Regarding iatrogenic fracture comminution, Rommens et al. reported that the pooled results showed that plating was superior to IMIL nailing, but fracture healing would not be affected even if additional comminution occurs at the fracture site.[14] We had 4 cases of intraoperative communition. Two A2 fractures got converted to B2 fractures and two A3 fractures converted to C2 fractures intraoperatively. All 4 fractures united without any further intervention or delay.

Zhao et al. in their systematic review comparing plating with IMIL nailing found that although similar rate of fracture union was found in both the groups, intramedullary nailing was associated with increased risk of intraoperative fracture comminution and postoperative decreased range of movements.[15] Ouyang et al. in their updated meta-analysis reported that both IMIL nailing and plate fixation could achieve a similar outcome on humeral shaft fractures. There has been no consensus regarding whether plating is superior to IMIL nailing. There have been no guidelines or recommendations for surgically treating humeral shaft fractures and there is a need for an evidence base to help surgeons make clinical decisions and develop optimal surgical treatment. Most studies suggest fracture union with plating occurs between 10 and 16 weeks.[16] In our study, 48 of the humerus shaft fractures united at an average of 13.4 weeks, which is comparable to the studies done by other authors.

Regarding the ASES score, though there was a trend favoring plating, the meta-analysis by Ma et al. in 2013 found no statistically significant differences between the two interventions.[4] In our study, the mean ASES score was 92 ± 1.45 at the time of final follow-up.

Garnavos et al. reported that all the 45 patients who sustained isolated traumatic humeral shaft fractures and who were treated with antegrade intramedullary nailing regained full painless range of shoulder joint motion. The authors proposed that a simple “in-out” incision on the rotator cuff, use of unreamed nails, and meticulous repair at the end of the procedure contributed to the uneventful shoulder range of motion postoperatively.[17] In 2011, a Cochrane systematic review indicated that IMIL nailing was associated with an increased risk of shoulder impingement, restriction of shoulder movement, and need for removal of the nail.[18] We followed the similar principles, but encountered 6 cases of shoulder impingement due to nail prominence. All 6 patients underwent nail removal after fracture union. One patient complained of shoulder pain even after implant exit. This may be attributed to the rotator cuff injury either during insertion or exit of the nail.

Diligent blunt dissection of the soft tissues and use of the sleeve system touching the bone during the drilling procedure prevents damage to vulnerable structures such as the axillary nerve, the circumflex artery, the long head of biceps, and the deltoid muscle.[19],[20] We did not encounter any of these intricacies due to proximal locking in our series. Distal locking screws pose a threat of injury to the median nerve and brachial artery, but no such cases have been reported to our knowledge. Most surgeons worldwide prefer to use 'open locking' technique for distal locking analogous to what was done in our study.[21] In order to avoid mini-open incision for distal locking, “bio” group of nails (e.g., Marchetti-Vincenzi Zimmer, True-Flex Encore, Fixion Disc-O-Tec, and Garnavos MERETE) were introduced, but this was at the expense of optimal fracture stability.[14],[18],[22]

Cheng and Lin suggested that antegrade and retrograde “fixed” nailing have similar treatment results, including healing rate and eventual functional recovery for middle third humeral fractures. However, they recommended that retrograde nailing should be used in patients with wide medullary canal or preexisting shoulder problems and antegrade nailing in younger patients or those with a small medullary canal.[23] We did antegrade nailing in all our cases.

Ma et al., in their meta-analysis comparing the plating and nailing procedures for humeral shaft fractures, concluded that iatrogenic radial nerve injury was reported in all the studies, but there was no significant difference between the two fixation methods (RR = 0.72 95% CI: 0.35–1.47).[4] In our study, we encountered one case of iatrogenic radial nerve palsy that recovered spontaneously at 6 weeks of follow-up.

In most of our fractures, we achieved closed reduction except for 5 cases where open reduction had to be done. A small incision measuring approximately 1 inch was made along the line of Henry's anterolateral approach for humerus shaft directly over the fracture site to aid the guidewire to pass across the fracture site to the distal fragment. Out of the 5 fractures, three of them were 12A1 spiral fractures, one 12A3, and one 12B1 fracture. In our experience, we found that the spiral fractures were unstable and getting a perfect cortical contact was difficult by closed reduction. In another case, spiral fracture with a wedge component was present which required open reduction. One case of transverse fracture required open reduction due to soft tissue interposition at the fracture site.

Literature suggests the impairment of the blood supply and wide exposure may increase the risk of infection with plating, especially in the middle and distal parts of the humeral shaft.[4] In our study, there was one case of infection noted at the nail entry site. Culture grew methicillin-resistant Staphylococcus aureus and infection subsided with intravenous linezolid.

A very important concern about nailing is selecting the right length. A short nail can lead to deep insertion of the nail into the humeral head, hence making implant removal extremely difficult or it may not allow impaction into the distal part of the humerus. On the other hand, a long nail may cause fracture site distraction and also impingement of the shoulder due to prominence.[24],[25],[26] Four cases showed distraction at fracture site, out of which 2 cases needed intervention in the form of dynamization and bone marrow infiltration and one fracture was bone grafted. All of which eventually went on to unite.

The pooled results in respect to implant failure and the reoperation rates showed that plating was superior to IMIL nailing. In the plating groups, the rotation force and shear force at the fracture site resulted in higher stress concentrations on the implant, whereas in the IMIL nailing groups, implant failure usually occurred at the site of the distal or proximal locking screw. This complication was frequently noted during the patient rehabilitation postoperatively.[4] We had no implant failures in our study.

 Conclusion



Humerus nail fixation is a technique with shorter operative time, minimal exposure, and less blood loss. Preservation of fracture hematoma, soft tissue, and periosteum around the fracture justifies the fact for high rates of union and excellent functional outcome. Avoiding nailing the fracture in distraction, achieving adequate fixation stability, and countersinking the tip of the nail into the subchondral bone have been found to be of paramount importance to reduce the incidence of delayed union/nonunion rate, prevent shoulder impingement, and help achieve preinjury status as early as possible.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Tsai CH, Fong YC, Chen YH, Hsu CJ, Chang CH, Hsu HC. The epidemiology of traumatic humeral shaft fractures in Taiwan. Int Orthop 2009;33:463-7.
2Garnavos C. Intramedullary nailing for humeral shaft fractures: The misunderstood poor relative. Curr Orthop 2001;15:68-75.
3Brumback RJ. The rationales of interlocking nailing of the femur, tibia, and humerus. Clin Orthop Relat Res 1996;(324):292-320.
4Ma J, Xing D, Ma X, Gao F, Wei Q, Jia H, et al. Intramedullary nail versus dynamic compression plate fixation in treating humeral shaft fractures: Grading the evidence through a meta-analysis. PLoS One 2013;8:e82075.
5Sarmiento A, Waddell JP, Latta LL. Diaphyseal humeral fractures: Treatment options. Instr Course Lect 2002;51:257-69.
6Singisetti K, Ambedkar M. Nailing versus plating in humerus shaft fractures: A prospective comparative study. Int Orthop 2010;34:571-6.
7Putti AB, Uppin RB, Putti BB. Locked intramedullary nailing versus dynamic compression plating for humerus shaft fractures. J Orthop Surg 2009;17:139-41.
8Raghavendra S, Bhalodiya HP. Internal fixation of fractures of the shaft of the humerus by dynamic compression plate or intramedullary nail: A prospective study. Indian J Orthop 2007;41:214-8.
9Changulani M, Jain UK. Comparison of humerus intramedullary nail and dynamic compression plate for the management of diaphyseal fractures of humerus. A randomised prospective study [abstract]. J Bone Joint Surg 2008;90 Suppl 2:349-50.
10Dalton JE, Salkeld SL, Satterwhite YE, Cook SD. A biomechanical comparison of intramedullary nailing systems for the humerus. J Orthop Trauma 1993;7:367-74.
11Garnavos C. Diaphyseal humeral fractures and intramedullary nailing: Can we improve outcomes? Indian J Orthop 2011;45:208-15.
12Blum J, Rommens PM, Janzing H. The unreamed humeral nail--a biological osteosynthesis of the upper arm. Acta Chir Belg 1997;97:184-9.
13Schopfer A, Hearn TC, Malisano L, Powell JN, Kellam JF. Comparison of torsional strength of humeral intramedullary nailing: A cadaveric study. J Orthop Trauma 1994;8:414-21.
14Rommens PM, Kuechle R, Bord T, Lewens T, Engelmann R, Blum J. Humeral nailing revisited. Injury 2008;39:1319-28.
15Zhao JG, Wang J, Wang C, Kan SL. Intramedullary nail versus plate fixation for humeral shaft fractures: A systematic review of overlapping meta-analyses. Medicine (Baltimore) 2015;94:e599.
16Ouyang H, Xiong J, Xiang P, Cui Z, Chen L, Yu B. Plate versus intramedullary nail fixation in the treatment of humeral shaft fractures: An updated meta-analysis. J Shoulder Elbow Surg 2013;22:387-95.
17Garnavos C, Lasanianos N, Kanakaris NK, Arnaoutoglou C, Papathanasopoulou V, Xenakis T. A new modular nail for the diaphyseal fractures of the humerus. Injury 2009;40:604-10.
18Kurup H, Hossain M, Andrew JG. Dynamic compression plating versus locked intramedullary nailing for humeral shaft fractures in adults. Cochrane Database Syst Rev 2011;15:CD005959.
19Bhandari M, Devereaux PJ, McKee MD, Schemitsch EH. Compression plating versus intramedullary nailing of humeral shaft fractures--a meta-analysis. Acta Orthop 2006;77:279-84.
20Prince EJ, Breien KM, Fehringer EV, Mormino MA. The relationship of proximal locking screws to the axillary nerve during antegrade humeral nail insertion of four commercially available implants. J Orthop Trauma 2004;18:585-8.
21Rupp RE, Chrissos MG, Ebraheim NA. The risk of neurovascular injury with distal locking screws of humeral intramedullary nails. Orthopedics 1996;19:593-5.
22Garnavos C. Humeral nails: When to choose what and how to use. Curr Orthop 2005;19:294-304.
23Cheng HR, Lin J. Prospective randomized comparative study of antegrade and retrograde locked nailing for middle humeral shaft fracture. J Trauma 2008;65:94-102.
24Lin J, Shen PW, Hou SM. Complications of locked nailing in humeral shaft fractures. J Trauma 2003;54:943-9.
25Farragos AF, Schemitsch EH, McKee MD. Complications of intramedullary nailing for fractures of the humeral shaft: A review. J Orthop Trauma 1999;13:258-67.
26Lin J, Inoue N, Valdevit A, Hang YS, Hou SM, Chao EY. Biomechanical comparison of antegrade and retrograde nailing of humeral shaft fracture. Clin Orthop Relat Res 1998;351:203-13.