Physicians use two main criteria to determine whether surgery is indicated:

Different surgical treatments are based on the type or severity of the fracture. Tension band wiring is still the most accepted treatment for displaced patella fractures.^9–11 Weber and colleagues¹² noted that if stability and early range of motion (ROM) is to be performed, there must be a stable repair of the fracture site to avoid displacement of the repair. They noted increased stability by repairing cadaveric patella fractures with a technique in which the wire is anchored directly in bone. They also noted that the retinaculum should be repaired because it added to stability. Bostman and colleagues¹³ examined several different approaches and techniques to repair patella fractures and discovered the tension band wiring procedure to be far superior to other methods, but using screws with tension band technique appears the strongest.^14–16 With the production of Kevlar sutures, the use of sutures to fix patella fractures has been reported.^17–19

Smith and associates²⁰ performed a retrospective review of postoperative complications after ORIF of patella fractures. They followed 51 patients treated with the tension band fixation technique until complete healing had occurred at a minimum of 4 months. The authors’ objective was to focus on acute, short-term complications after ORIF of patella fracture. Although the study did not specifically assess clinical parameters, such as pain or strength, it did point out two important factors to consider during rehabilitation. Approximately 22% of the patella fractures treated with modified tension band wiring and early ROM displaced significantly during the early postoperative period.

Failure of fixation was related to unprotected ambulation and noncompliance. Patient noncompliance in restricting early ROM and weight bearing can cause failure of even technically correct tension band wire fixation.^3,13,21–23

Joint congruity must be restored to decrease the development of arthritis, and the extensor mechanism must be restored to regain full extension. Most patients with displaced fractures are candidates for ORIF. If the patient was ambulatory before the injury and can medically tolerate surgery, then surgery should be performed regardless of age. Situations in which nonambulatory patients with patella fractures lack lower-extremity (LE) function and sensation (neurologic impairment) can be managed conservatively.

Patients with simple two-part fractures have a better chance of a successful outcome than those with highly comminuted fractures. The variability of outcomes relates to the degree of fixation and the ability of the fracture site or sites to consolidate. In some cases of irreducible comminution, the fragments may have to be removed, resulting in a partial or total patellectomy.^4,21,24–32 Patellectomy procedures have a lower success rate than stable internal fixation procedures.^33–36

Most methods of ORIF incorporate tension band wiring techniques.12,21,22,37,38 Makino and associates described an arthroscopically assisted technique.³⁹ The tension band wire is placed around the proximal and distal pole of the patella through the quadriceps and patella tendons. This wire compresses the fracture site. The surgeon maintains rotational control with one or two screws placed across the fracture site from the proximal to the distal pole. The tension band wire is passed under the k-wires or screws to add compressive and rotational stability to the fixation. Another method is to use cannulated screws through which the tension band wire may be passed. Suture can be used instead of wire in certain cases.^17–19

The integrity of the skin over the patella must be evaluated before surgery because of its potential to produce postoperative complications. The therapist should assess this area continually for infection and poor healing because vascular supply may have been disrupted during the trauma that caused the patella fracture.

Surgery is performed under either general or regional anesthesia. The patient is positioned supine, and a tourniquet is applied to the thigh. It is important that the knee can fully flex and extend so that the surgeon can determine the stable postoperative ROM. The leg is then prepped and draped in sterile fashion. If the skin allows, then a longitudinal midline incision is made over the patella. This incision (Fig. 26-1) is carried down to the peritenon, and full-thickness flaps are developed both medially and laterally to expose the entire patella and extensor mechanism. The peritenon is then incised to expose the fracture and the tendons. The fracture hematoma is débrided from the fracture site, and the raw cancellous bone is delineated to aid in fracture reduction. Two k-wires are then run from the fracture site of the proximal fragment and out the proximal pole of the patella (Fig. 26-2, A to C). The proximal and distal fragments of the patella are brought together to reduce the fracture. The fracture is then held together with bone-holding forceps while the knee is in extension (Fig. 26-2, D). The k-wires are passed back through the middle of the patella and out the distal pole. The bone-holding forceps are then removed (Fig. 26-2, E). Next the tension band wire is placed around the patella and k-wires. It should be positioned as close to the bone and k-wires as possible to minimize complications after ROM is initiated postoperatively (Fig. 26-2, F).

To place the tension wire as close to the bone and k-wire as possible, the surgeon usually passes a hollow needle under the k-wire and over the bone to guide the tension band wire. The tension band wire is then passed through the needle and brought around the patella. The two ends of the tension band wire are then twisted together with pliers to add tension to the system. The surgeon must be careful not to add too much tension to the wire because this may cause the wire to break early in the rehabilitation process (Fig. 26-2, G and H).

The surgeon then repairs the extensor mechanism. The medial and lateral retinacula are commonly torn in line with the fracture. These tears are simply repaired using nonabsorbable sutures. After this last repair, the surgeon checks the ROM to ensure that the patient can easily obtain full extension and at least 90° of flexion. The surgical site is then closed in the following order: first the peritenon, then the subcutaneous tissue, and finally the skin. The wound is dressed with a bulky dressing and placed in an immobilizer. A postoperative water-cooling system or ice pack may be used to assist with pain control immediately.

A partial patellectomy may be performed in patients with comminuted displaced fractures who have at least 50% of the patella remaining.³³ The inferior pole of the patella usually suffers the most trauma, resulting in its removal (Fig. 26-3, A). To do a partial patellectomy, the surgeon débrides the bone fragments from the tendon end and then weaves two large 5-0 nonabsorbable sutures into the tendon (5-0 FiberWire is now available that has the strength of 18-gauge wire and the flexibility of suture). The surgeon then drills two holes longitudinally into the remaining piece of the patella. The sutures in the tendon are brought through the holes in the patella and tied over the bone bridge formed by the two holes (Fig. 26-3, B and C).

Most patients require a second operation to remove the hardware placed in the patella.⁴⁰ The wires and sutures can become prominent and bother the patient during rehabilitation, slowing progress in gaining ROM.

The fixation of simple fractures is usually the most stable immediately after surgery. If the tension band wire is not placed right next to the screw, then the wire can cut through the tendon until it butts up against the screw, decreasing the compressive effect of the wire and possibly allowing the fracture to displace. Stable fixation of a simple fracture is usually strong enough to allow early passive range of motion (PROM). The amount of ROM is dictated by the surgical procedure and pain tolerance. Time frames to initiate physical therapy vary depending on the degree of comminution. The repair is most vulnerable between 4 to 6 weeks when the bone and tendon have not completely healed and the pins and wires have loosened. After 8 weeks, the repair should be stable enough to allow aggressive therapy with the goal of regaining full ROM.⁴¹

The exception to this time frame is the patient who has a comminuted fracture with unstable fixation. This type of situation may require 12 weeks before the initiation of therapy. Most patients return to preinjury activities (sports) by 6 months after surgery.

The treatment of patients who have undergone ORIF for patella fractures requires a cooperative approach from the orthopedist and the physical therapist (PT). This concept is most evident when considering the challenge in treating patients after surgery. The goal of treatment is to provide a structurally stable patellofemoral joint and allow for full functional recovery of the involved LE. Factors that influence the choice of treatment include the following:

Although rehabilitation after a patella fracture treated with ORIF is crucial, a wide range of protocols may be used depending on the factors listed previously, the physician’s chosen fixation technique, and the patient’s goals (which differ among athletes, sedentary adults, and children). The information the PT collects from both the physician and the patient aids in determining the design and time parameters of the rehabilitation program.

The remainder of this chapter deals only with the simple transverse fracture. However, the clinician is reminded to respect the previously discussed four factors influencing treatment when planning rehabilitation for all patella fractures.