Intramedullary nailing as a safe and efficient treatment option for all types of displaced proximal humeral fractures in geriatric patients: A retrospective evaluation of 49 patients treated with the new Targon PH + nail

Abstract

BACKGROUND:

Implant specific complications and outcome for the use of proximal humeral nails in different fracture types are not well described.

OBJECTIVE:

Evaluation of adverse effects and outcome of patients treated with the new Targon PH $+$ implant for proximal humeral fractures in a geriatric population.

METHODS:

A consecutive series of patients from a single institution was retrospectively evaluated. Adverse events (AE) were assessed from patients’ files and during follow-up examination. Current pain level was evaluated using the Visual Analogue Scale (VAS). The disability score of arm, shoulder and hand (DASH) as well as the Constant-Murley score were assessed. Patient satisfaction was evaluated by questionnaire.

RESULTS:

Forty-nine patients with a mean age of 72.0 $\pm$ 10.0 years were included with a follow-up of 2.2 years. Five patients showed twopart fractures (10%), 24 threepart fractures (50%) and 20 fourpart fractures (40%). Additional shaft fracture occurred in twelve cases (24%). Implant-related AE were recorded in six cases (12%). Pain under strain was moderate with a mean of 27.6 $\pm$ 27.1 mm. DASH score showed a mean of 25.9 $\pm$ 24.9. Constant score of the affected shoulder was 57 $\pm$ 23.8 with a mean difference of 16 points compared to reference shoulder. No significant differences in AE, VAS, DASH or Constant score could be found according to fracture groups. Most patients were satisfied with the surgical outcome (84%).

CONCLUSIONS:

The Targon PH $+$ nail demonstrated good functional results and low adverse events in geriatric patients. Additional studies including less experienced centres are required to further evaluate the possible benefits of this implant.

Keywords

Humerus fracture implant nailing outcome

1. Introduction

Proximal humeral fractures are the third most common fracture types amongst patients over 65 years old, after wrist and femoral neck fractures [1]. The incidence of proximal humeral fractures is rapidly increasing with age with women being affected twice as frequently as men [2]. This is likely to be caused by the increasing risk of osteoporosis with age and female sex [2, 3, 4, 5]. A prospective study over a 28 year period by Kannus et al. showed an increase in proximal humeral fractures by 15% per year in patients over the age of sixty, highlighting age as a main risk factor [6]. Palvanen et al. estimated that the number of shoulder fractures will increase threefold in the next 30 years mainly due to the increasing elderly population [7].

Surgical stabilization of dislocated multi-part fractures of the proximal humerus has shown superior results compared to conservative treatment and can be treated successfully with intramedullary or extramedullary implants [2, 8, 9, 10, 11]. Providing sufficient stabilization for early passive mobilization even in osteoporotic bone is the main target of all available implants. The use of angular stable plates often requires larger incisions with impairment of fragment’s blood supply which can cause non-union or soft tissue complications. The demand for a minimal invasive surgical approach therefore led to expansion of indications for intramedullary nailing from diaphyseal fractures towards metaphyseal fractures [3]. During the last decade short proximal humeral nails have therefore become available as well as long versions of these originally short nails [12, 13, 14, 15, 16]. The Targon PH $+$ nail was designed especially to provide improved angular stable fixation for all types of proximal humeral fractures including combined shaft fractures of the proximal third. All proximal locking screws show an elevated/increasing design to provide better hold in osteoporotic bone without interruption of anatomical blood supply even in a multi-fragment situation, therefore a right and left version is available (Fig. 1). However, the complications, efficacy and patient-reported outcome for different fracture types are not well described for the use of short and long versions of proximal humeral nails

2. Materials and method

2.1 Study population and outcomes of interest

All patients who received a Targon PH $+$ intramedullary nail (Aesculap AG, Tuttlingen, Germany; Fig. 1) due to one-sided proximal humeral fracture between July 2014 and February 2019 at a single trauma center were contacted by telephone and included in the study. Exclusion criteria during the follow-up period were: death, two-sided shoulder injuries and inability to complete the outcome measurements (i.e. dementia).

Figure 1.

The Targon PH $+$ ${}^{\@setsize{\tiny}{7pt}{\vipt}{\@vipt}{\textregistered}}$ Titanium intramedullary nail.

Primary objective was the analysis of treated fracture patterns, adverse effects associated with the procedure including implant and patient-related complications, as well as treatment failures.

Secondary objective was to determine the outcome by using different patient-reported outcome measures (PROMS).

2.2 Surgical procedure

Nail length and diameter as well as the necessary screw dimensions to maintain fixation were defined, using the preoperative x-rays. During surgery the patient was placed in the beach chair position on a radiolucent table fitted with a standard armrest. For implantation of the Targon PH $+$ nail, a deltoid splitting approach with an mean incision length of 4 cm (or extended as appropriate) at the anterolateral margin of the acromion was used. After a longitudinal transection of the clavipectoral fascia and the subacromial bursa, a reduction of the head fragments was done by indirect manipulation of the head fragments. For this procedure either Kirschner wires, an elevator, or a Schanz screw was used as a joystick for securing the fragments. After a longitudinal split of the supraspinatus tendon, a guide pin at the apex of the humeral head was positioned in both planes and the nail was inserted 3 to 4 mm below the cartilage level. Then, a minimum of three to four angular and sliding stable fixation screws were inserted into the head fragments, depending on the fracture pattern, the degree of instability and bone quality. A single or duplicate distal interlocking screw was placed through the nail via stab incisions, depending on individual bone quality. Each step of nail placement and locking screw insertion was controlled by fluoroscopy in true AP and axial views. The operations were performed by 25 surgeons. Operation time was defined as time from skin cut to wound closure. A postoperative x-ray examination was obtained from all patients to verify the reposition and correct positioning of the implant.

2.3 Postoperative treatment

After surgery, the affected arm was immobilized with a Gilchrist bandage for one day. On the second postoperative day an initial passive physiotherapeutic exercise regime was started. Active assisted shoulder movement was permitted as soon as wound healing was adequate. With all exercises to be performed below the pain threshold. Active physiotherapy was terminated six weeks after surgery.

2.4 Evaluation of patient data, clinical examinations and patient-reported outcomes

Basic clinical data was extracted from the existing patients file and included gender, age, weight, size, Body Mass Index (BMI), medical history and concomitant diseases and disabilities, the accident mechanism and the type of fracture (Neer classification), number of fracture fragments and the side affected. Also, additional fractures in other bones and joints were assessed. The index operation was documented by date, leading surgeon, duration of surgery, operative technique, the distal diameter, length of the inserted nail. Intraoperative and postoperative complications were assessed through the patient file as well.

During the follow-up examination all patients were assessed for complications. Current pain level of the affected shoulder and the reference shoulder was raised by using the Visual Analogue Scale with values between 0 (no pain) and 100 mm (maximum pain). Furthermore the disability score of arm, shoulder and hand (DASH) was assessed for the affected side, which ranges from a score value of no disability (0) to complete disability (100) [17]. The Constant-Murley score, consisting of the subscales pain, activities of daily living (ADL), mobility and strength with a maximum of 100 points (perfect functionality) was then used to assess the affected shoulder, in comparison to the contralateral shoulder [18, 19].

Patient’s satisfaction regarding the surgical result was evaluated by questionnaire (“Yes, I would undergo the operation again”, “I don’t know”, “no, I wouldn’t undergo the operation again”), and a four-stage scale for the overall satisfaction with the surgical result (“very satisfied”, “satisfied”, “unsatisfied”, “very unsatisfied”).

2.5 Statistical analysis

All data were obtained and analyzed retrospectively. Statistical analysis was performed using IBM SPSS Statistics for Windows (version 24, IBM Corp., Armonk, NY). Parametric data were analyzed using a Ttest. Nonparametric data was analyzed with the Mann-Whitney U test. For nominal data, the Pearson chi-square test or Fisher’s exact test were used. All reported $P$ values are two-tailed, with an alpha level $<$ 0.05 considered as significant. Unless otherwise stated, descriptive results are demonstrated as mean $\pm$ standard deviation and range.

2.6 Ethics

The local institutional ethics committee (Medical Association of Bavaria) gave consent to this study and approved conformity of the study to the Helsinki Declaration and to the local legislation. The study has the registration number 17095. The study is registered under ClinicalTrials.gov ID NCT02836366.

Table 1
Characteristics of patients and fracture patterns

	Total $n=$ 49 (100%)	Male $n=$ 15 (30.6%)	Female $n=$ 34 (69.4%)
Follow-up in years: mean $\pm$ SD (range)	2.2 years $\pm$ 1.1 (1.0–4.3)	2.1 $\pm$ 0.9 (1.1–4.1)	2.1 $\pm$ 1.2 (1.1–4.3)
Age in years: mean $\pm$ SD (range)	72.0 $\pm$ 10.0 (62–86)	71.7 $\pm$ 6.9 (63–86)	73.1 $\pm$ 8.4 (62–85)
BMI: mean $\pm$ SD (range)	27.7 $\pm$ 5.7 (17.5–43.3)	26.5 $\pm$ (20.5–34.2)	27.7 $\pm$ 6.2(17.5–43.3)
Side of fracture: $n$ (%)
Right	25 (51)	6 (40)	20 (59)
Left	24 (49)	9 (60)	14 (41)
Trauma impact: $n$ (%)
High impact	3 (6)	2 (13)	1 (3)
Low impact	46 (94)	13 (87)	33 (97)

3. Results

3.1 Patient characteristics

From a consecutive series of 54 patients 49 patients (90%) were included in the final data set. All patients were evaluated between September 2018 and March 2019 at the same institution with an average follow-up of 2.2 years (range: 1.0–4.3 years). The patient characteristics and fracture patterns are described in Table 1. There were no significant statistical differences between males and females regarding age follow-up, BMI, side, impact of trauma or fracture pattern. The majority of fractures were caused by low

Table 2
Follow-up data of patients according to fracture pattern

	Total	Two part	Three part	Four part	With additional shaft fracture
Number of patients ( $n$ , %)	49 (100)	5 (10)	24 (49)	20 (41)	12 (24)
Operation time in min (mean $\pm$	83.5 $\pm$ 27.9 (34–166)	66.8 $\pm$ 13.6 (49–84)	83.3 $\pm$ 30.2 (44–166)	87.2 $\pm$ 27.0 (34–137)	105.0 $\pm$ 27.1 ${}^{*}$ (55–141)
SD, range)
Adverse events ( $n$ , %)	12 (24)	1 (20)	4 (16)	7 (35)	4 (33)
VAS in rest in mm (mean $\pm$ SD,	4.2 $\pm$ 12.9 (0–70)	4.0 $\pm$ 8.9 (0–20)	2.9 $\pm$ 9.0 (0–30)	5.8 $\pm$ 17.1 (0–70)	5.0 $\pm$ 11.7 (0–30)
range)
VAS under strain in mm (mean $\pm$	27.6 $\pm$ 27.1 (0–80)	18.0 $\pm$ 30.3 (0–70)	25.7 $\pm$ 25.4 (0–80)	31.1 $\pm$ 28.8 (0–80)	37.5 $\pm$ 24.1 (0–80)
SD, range)
DASH score	25.9 $\pm$ 24.9 (2–95)	11.6 $\pm$ 17.3 (2–42)	24.5 $\pm$ 26.2 (3–95)	31.1 $\pm$ 24.3 (2–76)	29.1 $\pm$ 18.1 (4–54)
Constant score
Affected shoulder	57.0 $\pm$ 23.8 (18–82)	71.4 $\pm$ 15.1 (45–81)	51.1 $\pm$ 27.6 (16–82)	50.6 $\pm$ 18.7 (18–79)	54.3 $\pm$ 14.6 (29–78)
Reference shoulder	73.2 $\pm$ 20.5 (19–84)	78.1 $\pm$ 4.1 (45–82)	63.6 $\pm$ 27.6 (19–82)	70.4 $\pm$ 18.3 (59–84)	72.9 $\pm$ 10.6 (48–84)
Score rate of affected/reference	782	91.4	80.3	71.8	74.4
shoulder (%)

Table 3

Description of adverse events evaluated at follow-up

Fracture group	Type of AE/SAE	Serious?	Description AE/SAE	Linked to study product?	Outcome
Four-part fracture	Delayed bone consolidation	No	Delayed bone consolidation	Possible lack of stability	Disability as measured by the DASH score is still severe, with significant restrictions in function
Four-part fracture	Delayed bone consolidation	No	Delayed bone consolidation	Possible lack of stability	The current DASH score is very low, with a good functional result
Three-part fracture with shaft fracture	Delayed bone consolidation	No	Long immobilization of the shoulder (four weeks) with a delay of physiotherapy (after six weeks)	No	DASH score is still severe, with significant restrictions in function
Three-part fracture with shaft fracture	Screw loosening	No	Secondary dislocation of the fracture and loosening of a locking screw and screw perforation in the humeral head	Screw loosening in the absence of locking	At follow-up the patient is pain-free and free of any restrictions
Four-part fracture with additional shaft fracture	Screw loosening	No	The patient suffers from persistent pain from the shoulder into upper arm	Screw loosening (most distal screw)	The patient is still suffering from restricted function and pain, according to his DASH scoring
Three-part fracture	Screw loosening	Yes	Humeral head perforation by the screw and persistent pain and restrictions on movement lead to a secondary revision surger; the locking screw was removed and an arthrolysis of the shoulder joint was performe; further a synovectomy, and subacromial decompression was performed	Possibly due to screw migration/loosening	Shoulder mobility could be restored, with no further consequences
Three-part fracture	Lymphedema	No	Lymphedema and a small hematoma on the left arm reaching down to the hand occurred postoperatively	No	Resolved without further consequences
Four-part fracture	Lymphedema	No	Persistent swelling of the left upper arm most likely lymphedema	No	Resolved without further consequences
Four-part fracture	Lymphedema	No	Lymphedema	No	Resolved without further consequences
Two-part fracture with shaft fracture	Wound healing disorder	No	Local wound healing disorder	No	Resolved without further consequences
Four-part fracture	Wound healing disorder	No	A wound healing disorder in the proximal pole of the scar was observed. A wound dehiscence and formation of pus at the inflammation site was observed until a subcutaneous suture was removed	No	The inflammation healed with no consequences
Four-part fracture	Restricted mobility	Yes	Due to a function restriction of the left shoulder after implantation of Targon PH $+$ , a second surgical intervention became necessary. A shoulder arthroscopy with synovectomy and subacromial decompression for functional limitations after the osteosynthesis was performed	No	The restrictions of shoulder mobility could be restored, with no further consequences

impact (94%) which is concurrent with earlier findings in the elderly population. More female patients were included (69%) in our study group. Combined humeral head and shaft fractures occurred in 12 patients (18%). Additional fractures were observed in four patients: one dislocated fracture of the femoral neck, one pertrochanteric fracture of the femur, a serial rib fracture left, a fracture of the thoracic vertebra (Th1), and a patient with fractures of the lumbar vertebrae L2 to 4. Furthermore, one patient suffered a periprothetic fracture during the same fall. One further patient had an additional spiral shaft fracture of the humerus. In one case a shaft fracture and a dislocation fracture occurred in combination.

The following risk factors for adverse events were found during the evaluation: osteoporosis (nine patients, 18%), diabetes (eight cases, 16%), respiratory constraints (three cases, 6%), rivaroxaban therapy due to apoplexy in (two cases 4%) and advanced renal insufficiency in (two cases, 4%). Preoperatively 33 (67%) patients had no limitation or problems with other joints. Eight (16.33%) patients reported restrictions, current treatment or pain in other joints. One patient reported a proximal humeral fracture on the opposite side 32 years ago, treated conservatively. Due to a stair fall, in addition to the proximal humeral fracture an ipsilateral distal radius fracture occurred as accompanying injury.

3.2 Follow-up data on adverse events and patient-reported outcome measures

The duration of surgery ranged between 34 and 166 minutes (mean 83.5 $\pm$ 27.9), while duration of surgery for combined head and shaft fracture was significantly longer compared to cases with an isolated head fracture ( $p=$ 0.002). The preoperative measurement of distal nail-diameter was 7 mm in 17 (34%) patients and 8 mm in 32 (65%) patients respectively. The length of the intramedullary nails varied between 150 mm (63%), 200 mm (2%), 220 mm (6%), 240 mm (16%), 260 mm (8%), and 280 mm (4%).

Adverse events during the follow-up period were recorded in 12 patients (24%), and were related to the implant in six cases (12%). In two cases wound infections (4%) occurred and three lymphedemas (6%) were found. Although more adverse events occurred in the four-part fracture group, no significant difference could be found (Table 2). A detailed description of all adverse events including their presumed cause and final outcome at followup is reported in Table 3.

Pain at rest as measured with the VAS scale showed values between no pain (0 mm) and 70 mm. The average perceived pain was 4 mm. Pain under strain yielded the highest results in the four-parted fracture group with 38 mm.

Table 4
If you were faced with the same decision again, would you want to undergo the surgery again?

Yes, I would undergo the operation again	41 (83.7%)
I don’t know	6 (12.2%)
No, I wouldn’t undergo the operation again	2 (4.1%)

Functionality of the shoulder was assessed by the validated DASH score and ranged between 2 and 95 points, with an average of 25.9 points. The Constant score of the affected shoulder ranged between 18 and 82 points, with an average of 57 points, which was lower than the reference shoulder with 69 points. On average the difference between the affected and the reference shoulder was 16 points lower for the affected shoulder (76% compared to reference shoulder). No significant difference in VAS, DASH or Constant score could be found between the fracture groups (Table 2). The mean difference of Constant score (affected vs. unaffected side) was 16 points with no significant differences between the fracture pattern (Table 2). The satisfaction with the surgery was very high (Table 4). Forty-one out of the 49 asked patients (84%) would undergo the procedure again, if necessary. Six (12%) said they are not sure (“I don’t know”), and only two patients (4%) would not undergo the surgery again (Table 4).

4. Discussion

The main findings of this study are that geriatric patients treated with the Targon PH $+$ intramedullary nail demonstrated a low number of adverse events, low postoperative disability and good functional outcome in all types of treated fracture patterns. We were able to include two- to four-part fractures as well as combined humeral head and shaft fractures and demonstrated a good clinical outcome even in complex injuries. Furthermore, the inclusion of 25 different surgeons performing the operations points out the ease of use of the Targon PH $+$ nailing system.

The adverse effects of intramedullary nailing in the elderly are of high interest considering the high degree of frailty in the geriatric population. Due to the lack of sound meta-analysis with exact definitions of complications, the rates of intramedullary nailing of proximal humeral fractures remain unclear. Telpass et al. defined rotator cuff injury, malreduction, malunion and avascular necrosis of the humeral head as the most common adverse events in the head preserving therapy in the general population having reviewed 200 studies [20]. They also found a low rate of screw loosening in the analyzed studies which is concordant with our findings. In a recent study by Kloub et al. a considerable rate of avascular necrosis in four-part fractures was found with 25.7% avascular necrosis of the humeral head in a small study sample of 35 patients within an average follow-up of one year [21]. In contrast to earlier findings in our department we did not record a single case of avascular necrosis having used the Targon PH $+$ system [22]. Lange et al. stated an overall complication rate of 37% having used the precursor Targon PH in two- to four-part fractures. Most of their complication appeared to be implant-related [23]. Gracitelli et al. demonstrated a similar complication rate of 34% in a sample size of 36 patients (mean age of 64 years) [24]. Most of the adverse events found were attributed to the implant (19%) followed by injuries of the rotator cuff (13%) while this study noted a complication rate of 24% with 12% of them being implant-related. Although not significant there was a trend towards the occurrence of adverse events in the four part group but most of these adverse events were moderate. Only two patients in this group were found to have severe disability related to one case of delayed bone healing and one case of distal screw loosening. Recent investigations emphasized that reposition of dislocated four-part fractures can be difficult and present with decreased fracture healing or even pseudarthrosis independently of the implant used [22]. All other complications found in this study were related to soft-tissue complications which resolved in all cases at follow-up.

Improvement of the clinical outcome in the geriatric population compared to the reference shoulder was also found to be good in this study. The average Constant score in a non-injured 71 to 80-year-old population is described by Fialka et al. The Constant score of the healthy shoulder in our population seems to be perfectly in line with the cohort of the same age [25]. The postoperative Constant score of the injured side at follow-up was 57 points which is only 21% less than the score of the opposite side. Methews et al. reported a mean Constant score of 60 (28% less than the healthy side) on the injured side after intramedullary nailing and 84 on the healthy side, including patients under 50 years of age [26]. Having only included three- and four-part fractures Kloub et al. reported a mean Constant score of 63 in a younger study population with no assessment of the opposite side [21]. Lange et al. also found higher Constant scores counting 71 for two-part fractures, 75 for three-part fractures and 69 (four-part fractures respectively) [23]. The lower Constant score found in this study may be caused due to the inclusion of older patients (mean age 72.0 years). An earlier investigation in our center with the precursor implant showed a mean Constant score of 73 in a slightly younger collective (mean age of 69 years) [22]. The retrospective comparison of PROMS (CS, DASH and VAS) in our survey yielded no significant differences between the fracture groups, which stand in line with the findings of Lange et al. [23]. Although we noticed a moderately decreased Constant score, the patient satisfaction remained high (84%).

4.1 Strengths and limitations

There are several limitations of this study that have to be considered: First of all, the study was conducted retrospectively, with the inherent limitations. Radiological results further evaluating the influence of partial or complete head necrosis on the patient-reported outcome could not be obtained from all patients at follow-up. Avascular head necrosis usually develops during the first postoperative year and leads to impaired shoulder function. The good patient-reported outcome scores after a mean follow-up period of two-year nevertheless might indicate a low incidence of head necrosis in the study population. Second, this study only reports outcomes from one center with a longtime experience in intramedullary nailing. The major strength of the study is the number of treated fractures with an almost complete follow-up rate and inclusion of all types of fractures, including combined shaft and head fracture pattern.

5. Conclusion

The Targon PH $+$ nail demonstrated good functional results and low adverse events in geriatric patients. Additional studies including less experienced centers are required to further evaluate the possible benefits of this implant.

Footnotes

Acknowledgments

The authors would like to thank Frau Dr. Andrea Weiler (Aesculap, Germany) for her help during the organisation of this study and preparation of the manuscript.

Conflict of interest

None to report.

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