Arthrodesis of the Distal Interphalangeal (DIP) Joint of the Right Ring Finger for Arthritis

CHAPTER 1

Distal interphalangeal joint arthritis,or DIP joint arthritis,is second only to thumb basal joint arthritisin terms of the most symptomatic arthritis of the handoften necessitating surgical intervention.The technique being demonstrated hereis an arthrodesis of the distal interphalangeal joint.The indication for this techniqueis pain, deformity, and dysfunction.The technique being demonstrated hereis being performed under just local anesthesiain a wide-awake hand surgery fashion.

CHAPTER 2

You'll notice the patient herehas advanced arthritic changes of the ring finger DIP jointand has previously undergoneindex and middle finger DIP arthrodesis.Now the ring finger will be performed today.The technique requires the use of a headless compression screw.Here a 2.4 headless compression screw will be used.

Because the anesthesia being used is only a digital blockwith minimal lidocaine and epinephrinein the surgical site directly,a finger tourniquet is also being applied.

CHAPTER 3

The exposure is achieved entirely dorsally,so the incision is placed directlyacross the DIP joint dorsally.The incision is placed full thicknessthrough the skin, tendon, and the dorsal joint capsule.

CHAPTER 4

The joint is then opened,and the collaterals are also taken downto fully expose the joint.Care is taken not to injure the flexor tendondeep to the joint on the volar side.

CHAPTER 5

With the DIP joint fully exposedand the articular surface of the middle phalanx's headand the distal phalanx space exposed,a rongeur is used to debride off the articular cartilagedown to subchondral bone.I find it as easierto debride the middle phalanx's head firstbefore progressing to the distal phalanx space,because once the middle phalanx has been debridedthe distal phalanx space is better exposed.Generally, that distal sideis harder to debride of articular cartilage.It is often helpful to elevate the soft tissueoff of the dorsum of the distal phalanx space as shown here,even extending the flap distallyaround the nail may also be helpfulto fully expose the base to get the articular cartilage off.

CHAPTER 6

Once debrided, the fluoroscopy machine can be brought into confirm adequate debridement down to subchondral boneas well as to make sure adequate alignment has been restoredand any deformity corrected.This should be checked on both the PA and lateral views.Extra osteophytes that have been left behindcan also be assessed now and debrided away.

CHAPTER 7

Once satisfied with the joint debridementand alignment of the arthrodesis site,the guidewire for the headless compression screwis prepared to be inserted.I recommend using an inside-out techniquewhere the guidewire is first placed acrossthe distal phalanx in the desired center, center positionand then reversed into the middle phalanx.The inside-out technique is being shown here.Once happy with the alignment of the guidewire,that guidewire is then removed, flipped around,so that the blunt end is then directedinto the distal phalanxuntil only a bit of the sharp end is showingwithin the arthrodesis site.This will then allow the sharp endto be then placed retrograde into the middle phalanxunder direct visualization.Here, reversal of the pin and alignmentof the arthrodesis site is demonstrated on fluoroscopy.Once satisfied with the alignment,the pin can then be advanced into the middle phalanx.Here the pin can be seen being advanced retrogradeback into middle phalanxand then confirmed on fluoroscopy.

CHAPTER 8

Next, the screw length is measured.I generally find the available cannulated depth gaugesto be unhelpful,because the length of the screws should be suchthat it is countersunk below the head of the distal phalanxand should end within the isthmus of the middle phalanx.So oftentimes, what is more helpfulis simply measuring a screw on fluoroscopyto fit that desired length.

CHAPTER 9

Next, the cannulated drill is placed across the guidewireto create the path for the headless compression screw,and finally, the screw is placed across the guidewireand advance into the distal phalanx in a retrograde fashion.To achieve maximal compression across the arthrodesis site,I recommend compressing the arthrodesis site externallyto achieve what I refer to as macro-compressionand then allow the headless compression screwto achieve a micro-compression.

CHAPTER 10

Here, final position of the screw is confirmedmaking sure that the screw head is adequately countersunkwithin the distal phalanx,and that there is good contact and compressionwithout gapping across the arthrodesis site.Also, prior to washing the wound and closure,restoration of normal rotation of the fingershould also be confirmedwith active flexion of the finger by the patientto make sure that the alignment is appropriate.

CHAPTER 11

If there is excessive redundancy of the skin,the proximal aspect of the skin can be excisedto improve the closure.Also, I find it helpful to repair the skinin a tenodermodesis technique.That involves repairing the skinand the underlying extensor tendon in one throw.That helps bulk up the closure dorsallyand cover the arthrodesis site.I use simple 4-0 nylon sutures as demonstrated here.Once closed, a soft dressing is applied.The patient is allowed to move the finger immediately.Obviously, the the DIP joint will not move,but early motion overall is encouraged.The dressing can be removed in two days,and the sutures can be removed in two weeks.

CHAPTER 12

I typically check radiographs againat two weeks and 12 weeks postoperativelyto confirm healing of the arthrodesis site.The patient is allowed to return to activitiesas tolerated immediately.The last thing to discuss is a word of warning.Sometimes fingers can be larger,and a larger screw can be used.In this case, a 2.4 screw was used.More commonly and more troublesomeis that some fingers are smallerand have difficulty accepting a headless screw.I would refer you to a study publishedby one of our former fellowswho looked at the diameter of screwsand found that some fingers require smaller screwssuch as closer to 2.0 to meet the diameterof the canal of the distal phalanx and middle phalanx.